Expression of herbicide metabolizing cytochromes

ABSTRACT

DNA sequences encoding herbicide metabolizing cytochrome P450 enzymes and iron-sulfur proteins that donate electrons to these enzymes, were introduced into plants and microorganisms rendering them able to produce the encoded gene products and to metabolize herbicides.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of U.S. Ser. No. 07/464,499 filed Jan.12, 1990, now abandoned which is a continuation-in-part of U.S. Ser. No.07/405,605 filed Sep. 11, 1989 now abandoned.

FIELD OF THE INVENTION

The invention relates to the introduction of DNA sequences fromStreptomyces griseolus into plants and microorganisms so that therecipient organisms produce the protein products of those genes and arethereby rendered capable of metabolizing the herbicide. These DNAsequences comprise those encoding herbicide metabolizing cytochromesP450 and iron-sulfur proteins that donate electrons to these cytochromesP450.

BACKGROUND OF THE INVENTION

The use of herbicides in weed control is a widely accepted agriculturalpractice. Our understanding of herbicide metabolism and degradation isstill in its infancy and is being actively investigated. Soilmicroorganisms were implicated in the degradation of herbicides by Joshiet al., Weed Sci. 33: 888-893, 1985. Sulfonylurea herbicides were shownto be co-metabolized by the soil bacterium Streptomyces griseolus byRomesser et al., Abstr. Ann. Mtg. Am. Soc. Microbiol. p. 248, 1985.Further study, as disclosed by Leto et al., Plant Physiol. 805: 5347(1986) and Romesser et al., Biochem. Biophys. Res. Comm. 140: 650-659(1986) showed that two cytochrome P450 enzymes designated P450SU1 andP450SU2, heme containing proteins of about 45,000 molecular weight, aresynthesized in cells of the bacterium Streptomyces griseolus when theyare grown in a medium containing any of several herbicides, Thesynthesis of these proteins by S. griseolus is detectable by UV/visdifference spectroscopy as described by Romesser, et al., BiochemBiophys. Res. Comm. 140: 650-659 (1986), analytical anion exchange andgel filtration chromatography as described by O'Keefe et al., PlantPhysiol. 805: 5347 (1986) and LDS gel electrophoresis as described byLeto et al., Plant Physiol. 805: 5348 (1986). Romesser et al., Biochem.Biophys. Res. Comm. 140: 650-659 (1986) and O'Keefe et al., RecentAdvances in Phytochemistry 21: 151-173 (1987), correlated the presenceof P450 enzymes with the ability of this organism to carry out a varietyof metabolic reactions on a number of sulfonylurea herbicides. Further,as discussed by Romesser et al., Biochem. Biophys. Res. Comm. 140:650-659, 1986, crude cell-free extracts from S. griseolus exhibitsulfometuron methyl (10010) hydroxylase activity only when they are fromcells grown in the presence of certain sulfonylureas, and differencespectra of the extracts resulting when chlorsulfuron (10013) orsulfometuron methyl (10010) is added suggest that the newly appearingcytochromes P450 bind to these compounds in a manner similar tosubstrate binding to cytochrome P450.

Additionally, genes that cause the breakdown of the active moieties ofherbicidal compounds may be incorporated in plants and cause said plantsto become resistant to the affected herbicide. Stalker et al., Science242: 419-422 (1988) describe the transfer of the gene from Klebsiellaozaenae encoding a specific nitrilase that converts the herbicidebromoxynil to metabolite 3,5-dibromo-4-hydroxybenzoic acid into tobaccoplants with the result that the tobacco plants became resistant tobromoxynil.

The major objects of the invention described here are the DNA sequencesencoding the two cytochromes P450. Other objects are the sequencesencoding their iron-sulfur protein electron donors. These sequences ofthis invention are from the bacterium Streptomyces griseolus ATCC11796.These two cytochromes P450 are capable of metabolizing sulfonylureacompounds and other herbicides. The two cytochromes P450 have beendesignated P450SU1 and P450SU2, and the two iron-sulfur proteins havebeen designated FeS-A and FeS-B.

In wild type Streptomyces griseolus, expression of cytochromes P450SU1,P450SU2, and iron-sulfur proteins FeS-A and FeS-B is induced by theaddition of sulfonylurea compounds. Although many sulfonylurea compoundsmay be metabolized by these cytochromes P450, now all are good inducersof these proteins. Thus optimal metabolism of many sulfonylureacompounds by wild type organisms can only be achieved by first inducingthe cytochromes P450 and iron-sulfur proteins with a sulfonylurea knownto be a good inducer. Organisms producing the P450 enzymesconstitutively or as a result of exposure to light would obviate theneed for inducing organisms with sulfonylureas to make them capable ofmetabolizing said sulfonylureas.

Thus, another object of this invention is to obviate the need to inducethe herbicide metabolizing cytochromes P450 and their iron-sulfurprotein electron donors in organisms (bacteria and plants) bytransforming said organisms with the genes of the herbicide metabolizingcytochromes P450 and where necessary, their iron-sulfur protein electrondonors contained in plasmids which permit the constitutive or lightinduced expression of the P450 enzymes and, where necessary, the ironsulfur proteins in the transformed organisms. Said transformed organismsare able to metabolize herbicides, both good and poor inducers, wheneverthey encounter them.

Typical cytochrome P-450 monooygenase systems from bacteria are similarto the P-450 CAM system from Pseudomonas putida (Sligar et al. in:Cytochrome P-450 Structure, Mechanism and Biochemistry, Ortiz deMontellano, ed. Plenum Press, New York (1986) pp. 429-504). This systemis comprised of a flavoprotein reductase (putidaredoxin reductase), alow molecular weight iron-sulfur protein (putidaredoxin) and thecytochrome P-450 (P-450 CAM). This systems of proteins functions totransfer reducing equivalents from a reduced pyridine nucleotidesequentially from putidaredoxin reductase, to putidaredoxin and then toP-450 CAM. It is important to note, however, that the specificity of theenzyme system for substrate resides solely on the P-450 protein, andthat the reductase and iron sulfur proteins are only important insofaras they provide the reducing equivalents to the P-450 necessary forcatalysis. Thus, another object of this invention is to place the genesfor sulfonylurea or herbicide metabolism in other organisms in such away as to utilize existing sources of reducing equivalents in theseorganisms to facilitate the function of the cytochrome P-450.

SUMMARY OF THE INVENTION

The bacterium, Streptomyces griseolus, contains two inducible geneswhich produce certain P450 enzymes which metabolize herbicidalcompounds. The two enzymes are called P450SU1 and P450SU2. It is knownthat these enzymes operate effectively only when certain iron sulfurproteins are available and when reductase proteins capable of donatingelectrons to the iron-sulfur proteins are available. Genes for ironsulfur proteins in Streptomyces griseolus are located adjacent to anddownstream of those for the P450 enzymes. The applicants have isolatedthe DNA sequences from S. griseolus which encode the P450 enzymesP450SU1 and P450SU2 and adjacent iron sulfur proteins, FeS-B and FeS-A.It has been found that either iron-sulfur protein FeS-A or FeS-B cantransfer reducing equivalents to either enzyme. The DNA sequencecomprising that for P450SU1 plus adjacent iron sulfur protein FeS-B isas detailed on pages 27 to 31 hereinafter starting at base pair number128 and ending at base pair number 1578. The DNA sequence comprisingthat for P450SU2 plus its adjacent iron sulfur protein FeS-A is asdetailed on pages 32 to 36 hereinafter starting at base pair number 195and ending at base pair number 1646. The applicants have constructednovel plasmids comprising the DNA sequences for P450SU1 plus FeS-B(i.e., pCAO400, pCAO401, pCAO200SU1#12, pCAO200SU1-FeS-B#9 pr pPAT108)and P450SU2 plus FeS-A (i.e., pCAO200-SU2-FeS-A#11 or pCS325) which cantransform bacteria. Bacteria, preferably bacteria of the genusStreptomyces and most preferably Streptomyces lividans transformed witha plasmid selected from pCAO400, pCAO401, pCAO200SU1-FeS-B#9, or pPAT108all comprising the DNA sequence encoding P450SU 1 plus FeS-B produce theP450SU 1 constitutively and metabolize herbicidal sulfonylurea compoundseven though no iron-sulfur protein reductase gene has been introducedinto these cells. Bacteria transformed with the plasmidpCAO200SU2-FeS-A#11 or pCS325, comprising the DNA sequence encodingP450SU2 plus the iron sulfur protein FeS-A produce P450SU2constitutively and can also metabolize herbicidal sulfonylurea compoundseven though no iron-sulfur protein reductase gene has been added.

Another embodiment of this invention is a method for the preparation ofmetabolites of herbicide compounds comprising incubating sulfonylurea orother herbicide compounds with cultures of bacteria, preferably bacteriaof the genus Streptomyces transformed with a plasmid selected frompCAO400, pCAO401, pCAO200SU1-FeS-B#9, pCAO200SU2-FeS-A#11, pPAT108 orpCS325.

Still another embodiment of this invention is a method for protectingplants in soil containing inhibitory amounts of herbicidal compoundscomprising soaking seedlings of plants in cultures of bacteria,preferably bacteria of the genus Streptomyces and most preferablyStreptomyces lividans transformed with a plasmid selected from pCAO400,pCAO401, pCAO200SU1-FeS-B#9 or pCAO200SU2-FeS-A#11 prior totransplanting the seedlings in the soil. A further embodiment of thisinvention is the bacteria coated seeds.

And another embodiment of this invention is the transformation ofplants, in particular those of horticultural or agronomic utility, withthese genes to make them capable of metabolizing sulfonylureaherbicides. For this purpose plasmids (i.e., pSU18, pSSU-SU111,pSSU-SU121, pCab-SU111, pCab-SU121, and pCab-SU131, pSuFe11, pSuFe21,pSuFe31 and pSuFe41) utilizing a fragment comprising sequences encodingP450SU1 and/or FeS-B with certain other DNA sequences preceding andfollowing the P450SU1 and/or FeS-B sequence have been engineered totransform plants with these genes. This may result in making saidtransformed plants susceptible to chemicals which lack, or contain onlyweakly, herbicidal activity by means of metabolizing the chemicals tocompounds exhibiting greater plant toxicity.

Metabolism of herbicides by transformed plants can make them resistantto said herbicides and reduce the buildup of herbicide residues in theplant. Cytochrome P450-mediated metabolism of sulfonylureas from a lesstoxic to a more toxic form results in a conditionally lethal phenotypeand could possibly be used for applications of tissue specific killingor for selection of events which disrupt gene expression.

Such transformed plants can include plants containing other mutant genesprior to their transformation with the P450SU1 or P450SU2 genes. Ofparticular interest are plants containing a mutant acetolactate synthaseenzyme which prevents or decreases inhibition. This enzyme catalyzes thefirst reaction in the synthesis of the amino acids valine, leucine, andisoleucine in plants and microorganisms. It is known that this enzyme ina variety of plants and miroorganisms is quite sensitive to inhibitionby sulfonylureas. It is theorized that transformed plants containingboth mutant acetolactate synthase enzymes which decrease or preventinhibition of the enzyme by sulfonylureas or other herbicides and P450cytochrome enzymes enabling plants to metabolize herbicides wouldpossibly result in plants showing even greater resistance to a widervariety of sulfonylurea compounds than that seen in plants containingmutant acetolactate synthase alone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a physical map, showing restriction endonuclease sites, ofplasmid pUC18-SU1-BamHI.

FIGS. 2A and 2B are each a physical map, showing restrictionendonuclease sites, of plasmids pCAO400 and pCAO401 respectively.

FIGS. 3A and 3B are each a physical map, showing restrictionendonuclease sites, of plasmids pCAO200SU1-FeS-B#9 and pCAO200SU1#12respectively.

FIG. 4 is a physical map, showing restriction endonuclease sites, ofplasmid pUC19-SU2-8.

FIG. shows Western blots as follows:

lane 1, 50 ng of purified cytochrome P450SU1;

lane 2, blank

lane 3, protein from S. lividans C37 grown with no sulfonylurea;

lane 4, protein from S. lividans C37 induced for six hours with 120 ppmof 10001;

lane 5, S. lividans transformed with pCAO400 grown with no sulfonylurea;

lane 6, S. lividans transformed with pCAO400 induced for six hours with120 ppm of 10001;

lane 7, 500 ng of purified cytochrome P450SU1.

FIG. 6 shows Western blots as follows:

lanes 1, protein extract of S. lividans transformed with pCAO401 andinduced with 120 ppm of 10001 for 24 hours;

lane 2, protein extract of S. lividans transformed with pCAO401 andinduced with 120 ppm of 10001 for 6 hours;

lane 3, protein extract of S. lividans transformed with pCAO401 andinduced with 120 ppm of 10001 for 3 hours;

lane 4, protein extract of S. lividans transformed with pCAO401 andgrown for 24 hours.

lane 5, protein extract from S. lividans transformed with pCAO400 andinduced with 120 ppm of 10001 for 24 hours;

lane 6, protein extract of S. lividans transformed with pCAO400 andinduced with 120 ppm of 10001 for 6 hours;

lane 7, protein extract of S. lividans transformed with pCAO400 andinduced with 120 ppm of 10001 for 3 hours;

lane 8, protein extract of S. lividans transformed with pCAO400 andgrown for 24 hours;

lane 9, 100 ng of purified cytochrome P450SU1.

FIG. 7 shows Western blots as follows:

lane 1, 100 ng of purified cytochrome P450SU1.

lane 2, 200 ng of purified cytochrome P450SU1.

lane 3, extracts of S. lividans transformed with pCAO200SU1#12;

lane 4, extracts of S. lividans transformed with pCAO200SU1-FeS-B#9.

FIG. 8 is a physical map, showing restriction endonuclease sites, ofpCAO200SU2-FeS-A#11.

FIG. 9 shows Western blots as follows:

lane 1, 100 ng of purified cytochrome P450SU2;

lane 2, extract (30 μg of protein) of S. lividans transformed withpCAO200SU2-FeS-A#11 grown without sulfonylurea;

lane 3, extract (30 μg of protein) of S. lividans transformed withpCAO200SU1#12 grown without sulfonylurea;

lane 4, extract (30 μg of protein) of S. lividans transformed withpCAO200SU1-FeS-A#9 grown without sulfonylurea;

FIG. 10A is a physical map showing restriction endonuclease sites ofpSU17.

FIG. 10B is a physical map showing restriction endonuclease sites ofpSSU-SU11.

FIG. 10C is a physical map showing restriction endonuclease sites ofpSSU-SU12.

FIG. 10D is a physical map showing restriction endonuclease sites ofpCab-SU11.

FIG. 10E is a physical map showing restriction endonuclease sites ofpCab-SU12.

FIG. 10F is a physical map showing restriction endonuclease sites ofpCab-SU13.

FIG. 11 depicts the N-dealkylation of 10015 to 10014.

FIG. 12A is the UV Absorbance Spectra for 10015 and 10014 standards.

FIG. 12B is the UV Absorbance Spectra for 10015 extracted from leaf andmetabolite extracted from leaf.

FIG. 13A depicts the metabolism of 10001 by tissues of transformedtobacco leaves to 10003 and 10002.

FIG. 13B depicts the disappearance over time of 10001.

FIG. 13 depicts the appearance over time of 10003.

FIG. 13B depicts the appearance over time of 10002.

FIG. 14 depicts the appearance of transformed and nontransformed tobaccoplants 22 days after spraying with 10015.

FIG. 15A is a physical map showing restriction endonuclease sits ofplasmid pSUFe1.

FIG. 15B is a physical map showing restriction endonuclease sits ofplasmid pSuFe2.

FIG. 15C is a physical map showing restriction endonuclease sits ofplasmid pSuFe3.

FIG. 15D is a physical map showing restriction endonuclease sites ofplasmid pSuFe4.

In FIGS. 15A through 15D, H3 represents HindIII, BMI represents BamHI,NCl represents NcoI, RI represents EcoRI, and BG2 represents BglII.

FIG. 16A is a physical map showing restriction endonuclease sites ofplasmid pPAT108.

FIG. 16B is a physical map showing restriction endonuclease sites ofplasmid pCS325.

FIGS. 17A to 17D are diagrams showing the construction of plasmid pSU17.

FIGS. 18A to 18D are diagrams showing the construction of plasmidpSUFe1.

FIGS. 19A and 19B are diagrams showing the construction of plasmidspSUU-SU11 and pSSU-SU12.

FIGS. 20A to 20C are diagrams showing the construction of plasmidspCab-SU11, pCab-SU12 and pCab-SU13.

FIGS. 21A to 21D are diagrams showing the construction of plasmidspSUFe3 and pSUFe4.

FIGS. 22A and 22B are diagrams showing the construction of plasmidpSUFe2.

FIGS. 23A and 23B are diagrams showing the construction of plasmidspAGS501 and pAGS502.

FIGS. 24A through 24D are diagrams showing the construction of plasmidpZ596.

FIG. 25A is a physical map showing restriction endonuclease sites ofplasmid pZ6A-SU1.

FIG. 25B is a physical map showing restriction endonuclease sites ofplasmid pZ6AT-SU1.

In FIGS. 17 through 22, P450SU1 represents the coding sequence for thecytochrome P450SU1 enzyme, CaMV35Sp is the 35S promoter of CaMV;Cab2215' is the 5' untranslated sequence of petunia gene for Cab22L;SSU301 is the coding sequence for the petunia gene for SSU; SSU3' is the3' untranslated sequence of the petunia gene for SSU301; SSUp is thepromoter of the petunia gene SSU301 gene; SSU-T is the sequence codingfor the chloroplast transmit peptide of the petunia SSU301 protein;SSU-M is the sequence doing for the mature petunia SSU301 protein; Cabpis the promoter of the petunia Cab22L gene; CabT is the sequence codingchloroplast transit; CabM is the sequence coding mature protein ofpetunia Cab22L protein; FeS-B is the sequence coding for FeS-B; and nos3' is the 3' untranslated region from nopaline synthase gene. In FIGS.23A and 23B, AMP means ampicillin resistance in bacteria, LB means leftborder of T-DNA, RB denotes right border of T-DNA, and NPT denoteskanamycin resistance in plants.

DETAILS OF THE INVENTION Definitions

PIPES: piperazine-N, N'-bis(2-ethanesulfonic acid)

MOPS: 3-(N-morpholino)propanesulfonic acid

ATCC: American Type Culture Collection depository located at 12301Parklawn Drive, Rockville, Md. 20852.

HPLC: high performance liquid chromatography

UV: ultraviolet light

Cytochromes P450SU1 and P450SU2: the names assigned to the twocytochrome P450 enzymes of this invention.

FeS-A and FeS-B: the names assigned to the two iron-sulfur proteins ofthis invention.

10001:N-[(4-chloro-6-methoxy-pyrimidin-2-yl)aminocarbonyl]-2-ethoxycarbonylbenzenesulfonamide

10002:N-[(4-chloro-6-hydroxy-pyrimidin-2-yl)aminocarbonyl]-2-ethoxycarbonylbenzenesulfonamide

10003:N-[(4-chloro-6-methoxy-pyrimidin-2-yl)aminocarbonyl]-2-carboxybenzenesulfonamide

10004:2-butyl-2,3-dihydro-N[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10005:2-(3-hydroxybutyl)-2,3-dihydro-N-[(4,6-dimethyoxypyrimidin-2-yl)aminocarbonyl]-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10006:N-[(4-methoxy-6-methyl-1,3,5-triazinyl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10007:N-[(4-methoxy-6-methyl-1,3,5-triazinyl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10008:N-[(4-methoxy-6-methyl-1,3,5-triazinyl)aminocarbonyl]-2-carboxybenzenesulfonamide

10009: N-[(4-methoxy-6-hydroxymethyl-1,3,5triazin-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10010:N-[(4,6-dimethylpyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10011:N-[(4-hydroxymethyl-6-methyl-pyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10012:N-[(4-carboxy-6-methylpyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

10013: N-[(4-methoxy-6-methyl-1,3,5triazinyl)aminocarbonyl]-2-chlorobenzenesulfonamide

10014:2,3-dihydro-N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-1,2-benzisothiazol-7-sulfonamide-1,1-dioxide

10015:2-methyl-ethyl-2,3-dihydro-N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-1,2-7-sulfonamide-1,1-dioxide

10016:N-[(4-methoxy-6-methylpyrimidin-2-yl)aminocarbonyl]-5-dimethylamino-1-naphthalenesulfonamide

10017: 3-cyclohexyl-1-methyl-6-dimethylamino-S-triazine-2,4(1H, 3H)dione

10018: 4-amino-6-tert-butyl-3-(methylthio)-AS-triazin-5(4)-one

10019: 3-(3-chloro-p-tolyl)-1,1-dimethylurea

10020:7-chloro-5-fluoro-4-(2,3,4,5,6,7-hexahydro-1,3-dioxo-1H-isoindol-2-yl)-2,3-dihydro-2-benzofurancarboxylicacid, methyl ester

10021:2-[4-chloro-6-(ethylamino-1,3,5-triazin-2-yl)amino[-2-methylpropanenitrile

10022: 1-methyl-2(1H)-pyrimidinone

10023: 3,5-dibromo-4-hydroxybenzonitrile

10024:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2-ethyl-2,3-dihydro-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10025:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]2,3-dihydro-2-(phenylmethyl)-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10026:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl[-2-(2-fluorethyl)-2,3-dihydro-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10027:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl[-2,3-dihydro-2-propyl-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10028:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydro-2-(2-propenyl)-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10029:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2-methyl-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10030:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydro-2-(2-methylpropyl)-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10031:2-acetyl-N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydro-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10032:N-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl]-2,3-dihydro-2-(trimethylsilylmethyl)-1,2-benzisothiazole-7-sulfonamide-1,1-dioxide

10033:N-(2-chloro-6-methylphenyl)-5,7-dimethyl-1,2,4-triazolo-1,5A-pyrimidine-2-sulfonamide

10034:2-[(4,5-dihydro-4-methyl-4-(1-methylethyl)-1H-imidazol-2-yl)-5-ethyl-3-pyridinecarboxylicacid

10035:2-[(4,5-dihydro-4-methyl-4-(1methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylicacid

10036: N-(2,6-dichlorophenyl)-4,6-dimethyl-2-pyrimidinesulfonamide

In the context of this disclosure, a number of terms shall be utilized.As used herein, the terms "promoter" and "promoter region" refers to asequence of DNA, usually upstream (5') to the protein coding sequence ofa structural gene, which controls the expression of the coding region byproviding the recognition for the RNA polymerase and/or other factorsrequired for transcription to start at the correct site. Promotersequences are necessary but not always sufficient to drive theexpression of the gene.

A "fragment" constitutes a fraction of the DNA sequence of theparticular region.

"Nucleic acid" refers to a molecule which can be single stranded ordouble stranded, composed of monomers (nucleotides) containing a sugar,phosphate and either a purine or pyrimidine. In bacteria in higherplants, "deoxyribonucleic acid" (DNA) refers to the genetic materialwhile "ribonucleic acid" (RNA) is involved in the translation of theinformation from DNA into proteins.

"Regulation" and "regulate" refer to the modulation of gene expressioncontrolled by DNA sequence elements located primarily, but notexclusively upstream of (5' to) the transcription start of a gene.Regulation may result in an all or none response to a stimulation, or itmay result in variations in the level of gene expression.

The term "coding sequence" refers to that portion of a gene encoding aprotein, polypeptide, or a portion thereof, and excluding the regulatorysequences which drive the initiation of transcription. A coding sequencemay be one normally found in the cell or it may be one not normallyfound in a cellular location wherein it is introduced, in which case itis termed a heteroogous gene. A heterologous gene may be derived inwhole or in part from any source known to the art, including a bacterialgenome or episome, eukaryotic nuclear or plasmid DNA, cDNA, orchemically synthesized DNA. The coding sequence may constitute anuninterrupted coding region or it may include one or more intronsbounded by appropriate splice junctions. The coding sequence may be acomposite of segments derived from different sources, naturallyoccurring or synthetic.

A "3' downstream region" (or "3' end") refers to that portion of a genecomprising a DNA segment, excluding the 5' sequence which drives theinitiation of transcription and the coding sequence of the gene, thatcontain a polyadenylation signal in eukaryotes and any other regulatorysignals capable of affecting mRNA processing or gene expression. Thepolyadenylation signal in eukaryotes is usually characterized byaffecting the addition of polyadenylic acid tracts to the 3' end of themRNA precursor. Polyadenylation signals are commonly recognized by thepresence of homology to the canonical form 5'-AATAAA-3', althoughvariations are not uncommon.

The term "construction" or "construct" refers to a plasmid, virus,autonomously replicating sequence, phage or nucleotide sequence, linearor circular, or a single- or double-stranded DNA or RNA, derived fromany source, in which a number of nucleotide sequences have been joinedor recombined into a unique construction which is capable of introducinga promoter fragment with DNA sequence for selected gene product alongwith appropriate 3' untranslated sequence into a plant cell.

As used herein, "plant" refers to whole plants and plant-derivedtissues.

As used herein, "transformation" is the acquisition of new genes in acell after the incorporation of nucleic acid (usually double strandedDNA).

The term, "operably linked" refers to the chemical fusion of twofragments of DNA in a proper orientation and reading frame to betranscribed into functional RNA.

The term "expression" as used herein is intended to mean thetranscription and translation to gene product from a gene coding for thesequence of the gene product. In the expression, a DNA chain coding forthe sequence of gene product is first transcribed to a complementary RNAwhich is often a messenger RNA and, then, the thus transcribed messengerRNA is translated into the above-mentioned gene product if the geneproduct is a protein.

The "translation initiation signal" refers to a unit of threenucleotides (codon) in a nucleic acid that specifies the initiation ofprotein synthesis.

The term "plasmid" as used herein refers to an extra chromosomal elementoften carrying genes which are not part of the central metabolism of thecell, and usually in the form of circular double-stranded DNA molecules.

The term "restriction endonuclease" refers to an enzyme which binds andcuts within a specific nucleotide sequence within double-stranded DNA.

The term "T-DNA" is the segment of DNA from a plasmid transferred fromsoil bacterium Agrobacterium to the genome of its plant host.

The techniques of DNA recombination used throughout this invention areknown to those skilled in the art and generally described in Maniatis etal., Molecular Cloning: A Laboratory Manual, Cold Spring HarborLaboratory, Cold Spring Harbor, N.Y., (1982).

Materials and General Methods

Restriction endonucleases, DNA polymerases, DNA ligase and other DNAmodification enzymes were purchased from Bethesda Research Laboratories,Gaithersburg, Md. 20877; New England Biolabs, Beverly, Mass. 01915; andBoehringer-Mannheim Biochemicals, Indianapolis Ind. 46250.

Media

Media for growth of Streptomyces cultures are YEME broth, sporulationbroth, trypticase soy broth and minimal medium.

YEME broth consists of 340 g sucrose, 3.0 g yeast extract (Difco), 5.0 gpeptone (Difco), 3.0 g malt extract broth (Oxoid) and 10 g glucosedissolved in water to 1 liter.

Sporulation broth consists of 1.0 g yeast extract (Difco), 1.0 g beefextract (Difco), 2.0 g tryptose (Difco), 10 g glucose and approximately1 mg FeSO₄ dissolved in water to 1 liter.

Trypticase soy broth consists of 17.0 g pancreatic digest of casein, 3.0g papaic digest of soybean meal, 5.0 g NaCl, 5.0 g K₂ HPO₄, and 2.5 gglucose per liter of water.

Minimal medium consists of 0.5 g K₂ HPO₄, 0.6 g L-asparagine, 0.3 g KOH,0.4 g MgSO₄.7H₂ O, 0.01 g FeSO₄.7H₂ O, 3.07 g glycerol per liter of H₂O. To make solid medium, 15 g of agar is added per liter of medium.

Culturing of Streptomyces

Streptomyces cultures are grown in sporulation, YEME or trypticase soybroth at 30° C. with shaking at 150-300 rpm in an orbital shaker.

Harvesting bacterial cells

Bacterial cells are harvested by centrifuging them at 6,000-12,000×g for10-20 minutes at 4° C. Cells are washed in 0.1M PIPES buffer pH 7.0 or0.1M MOPS pH 7.2 and collected by again centrifuging them at6,000-12,000×g for 10-20 minutes at 4° C.

Cell extracts

Cell extracts from Streptomyces are obtained by resuspending harvestedcells in 1 to 3 cell volumes of 0.1M PIPES buffer pH 6.8-7.0 anddisrupting them by means of a French pressure cell (20,000 psi). Thecell debris is removed by centrifugation at 10,000-12,000×g for 10-20minutes in a microcentrifuge at 4° C. The protein concentrations of eachextract is quantitated using the method of Bradford (Anal. Biochem. 72:247-254 (1976)).

Western blot analyses

Western blot analysis of proteins is performed by separating theproteins by SDS polyacrylamide gel electrophoresis (Laemmli, Nature 227:680, 1970, herein incorporated by reference) and then transferring theproteins to nitrocellulose and detecting the protein of interest withantibody specific for the protein as described by Towbin et al., Proc.Natl. Acad. Sci. U.S.A. 76: 4350-4354 (1979) and Bio-Rad bulletin 88585-0335. (Bio-Rad Laboratories, Richmond, Calif. 94804), each hereinincorporated by reference. Antiserum to cytochrome P450SU1 was thatdescribed by O'Keefe et al., Recent Advances in Phytochemistry 21:151-173 (1987), herein incorporated by reference. Antiserum tocytochrome P450SU2 was prepared as was that for P450SU1 except thatcytochrome P450SU2 was isolated from S. griseolus PH2042, a mutant thatdoes not make cytochrome P450SU1.

HPLC analysis of herbicide compounds

Herbicides and their metabolites are measured by HPLC as described byRomesser et al., BBRC 140: 650-659 (1986), herein incorporated byreference, except that 0.1% H₃ PO₄ is used in both solvents.Chromatographic identity and quantitation of the herbicides and theirresulting metabolites is determined by comparing themchromatographically with authentic standard compounds. Identity of theresulting metabolites is also confirmed by UV spectroscopy.

Isolation of S. griseolus mutants without P450SU1

Mutants of S. griseolus that do not make cytochrome P450SU1, but do makecytochrome P450SU2 were isolated by treating spores of S. griseolus ATCC11796 with 2 mg/ml nitrosoguanidine for 30 minutes at room temperature.The mutagenized spores were diluted and plated on a rich medium andincubated at 30° C. until mature colonies had formed. Single coloniesfrom these plates were then patched onto minimal medium. The colonieswere incubated for several days, then, a soft agar overlay containing 20mg/ml of the fluorescent sulfonylurea 10016 was poured over the platefollowed by further incubation at 30° C. The plates were then viewedunder short wave UV light. Large non-fluorescent zones were observedaround a majority of the colonies that had metabolized the sulfonylurea.Those colonies which showed a reduced ability to metabolize 10016 (i.e.,smaller non-fluorescent zones were observed) were considered potentialmutants. A number of such colonies were isolated and found to makecytochrome P450SU2 but not cytochrome P450SU1. Three of these mutants,S. griseolus PH2001, PH2003 and PH2042, were used in the examplesdescribed below. These mutants have similar properties.

Amino acid sequencing

Cytochromes P450SU1 and P450SU2 were purified using the methodsdescribed by O'Keefe et al., Arch. Microbiol. 149: 406-412 (1988),herein incorporated by reference. Purified, native cytochromes P450SU1and P450SU2 were reacted with iodoacetic acid to make thecarboxymethyl-derivatives of each protein which were subsequentlysubjected to amino acid analysis and automated Edman degradation aminoacid sequencing using methods well known to those skilled in the art(Methods of Protein Microcharacterization (1986), Humana Press, Inc.,Clifton, N.J., J. E. Shively, ed., herein incorporated by reference).Two iron-sulfur proteins, FeS-A and FeS-B, which can be used in thereconstitution of cytochrome P450 enzymatic activity in the presence ofcytochrome P450SU1 or P450SU2 and spinach ferredoxin:NADP oxidoreductase(commercially available) were purified from the same extracts ofsulfonylurea induced S. griseolus cells used to purify cytochromesP450SU1 and P450SU2. The iron-sulfur proteins were collected as a singlepeak from the anion exchange column used in the P450 purification(O'Keefe et al., Arch Microbiol. 149: 406-412 (1988), hereinincorporated by reference, and were detected by their spectral propertyof having nearly equal absorbance at both 460 nm and 420 nm. Theiron-sulfur proteins isolated in this way were subsequently concentratedby ultrafiltration. Determination of the acid labile iron and sulfidecontent confirmed the proteins to be iron-sulfur proteins.Carboxymethylation of the iron sulfur proteins and reverse phasechromatography separated the iron-sulfur protein preparation into twoseparate apoproteins designated FeS-A and FeS-B which were subjected toamino acid analysis and automated Edman degradation amino acidsequencing using methods well known to those skilled in the art (Methodsof Protein Microcharacterization (1986), Humana Press, Inc., Clifton,N.J., J. E. Shively, ed.). The amino terminal amino acid sequences andamino acid compositions of P450SU1, P450SU2, FeS-A, and FeS-B are shownbelow. ##STR1##

    ______________________________________                                        Amino acid compositions of cytochromes P450SU1,                               P450SU2, FeS-A, and FeS-B                                                            Mole % of each Amino Acid                                              Amino Acid                                                                             P450SU1   P450SU2   FeS-A   FeS-B                                    ______________________________________                                        Cys      0.7       1.3       4.7     3.4                                      Asx      9.5       9.0       12.5    13.2                                     Thr      6.7       7.3       6.0     9.8                                      Ser      4.3       3.3       1.6     2.9                                      Glx      11.4      9.2       8.2     7.9                                      Pro      6.7       6.9       6.5     4.3                                      Gly      7.8       7.1       4.9     9.0                                      Ala      11.4      12.3      18.9    14.7                                     Val      7.8       6.9       10.8    12.3                                     Met      1.7       1.9       1.2     1.2                                      Ile      3.1       3.3       5.7     1.1                                      Leu      11.4      11.8      6.7     6.2                                      Tyr      1.9       0.9       0       0                                        Phe      3.1       3.1       1.6     1.5                                      His      2.6       2.4       3.0     1.4                                      Lys      1.4       1.2       1.7     0.3                                      Trp      0.5       0.5       0       0                                        Arg      8.1       11.6      6.1     10.9                                     ______________________________________                                    

Cloning the genes for cytochrome P450SU1, cytochrome P450SU2, FeS-A andFeS-B from Streptomyces griseolus ATCC11796

DNA encoding the gene for cytochrome P450SU1 was cloned from S.griseolus DNA. Bacteriophages containing the proper sequences of DNAwere obtained by first identifying clones of transformed E. coli thatexpressed the SU1 protein. This was done by using antibody specific forcytochrome P450SU1 as described by O'Keefe et al., Recent Advances inPhytochemistry 21: 151-173 (1987), using methods well known to thoseskilled in the art (Young et al., Proc. Natl. Acad. Sci. U.S.A. 80:1194-1198 (1983) and Young et al., Science 222: 778-782 (1983)), each ofwhich is herein incorporated by reference. Restriction endonuclease maps(Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y.) were made of the isolated S.griseolus DNA and they indicated that a 2.4 kb BamHI restrictionendonuclease fragment should contain the complete cytochrome P450SU1coding sequence. This 2.4 kb restriction endonuclease fragment wascloned from S. griseolus DNA into the plasmid pUC 18 using methods wellknown to those skilled in the art (Maniatis et al., Molecular Cloning: aLaboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y.;Frischauf et al., J. Mol. Biol. 170: 827-842 (1983), each hereinincorporated by reference), to make the plasmid pUC18-SU1-BamHI.Subsequent DNA sequence analysis, shown below, indicated that the codingsequence for the FeS-B protein is also encoded on this 2.4 kb BamHIfragment, being just downstream from the sequence for SU1. The plasmidpUC18-SU1-BamHI has been deposited in the American Type Culturecollection and has ATCC accession number 67780. A restrictionendonuclease map of pUC18-SU1-BamHI is shown in FIG. 1.

A 2.0 kb BamHI restriction endonuclease DNA fragment thatcross-hybridized to the 2.4 kb BamHI fragment encoding cytochromeP450SU1 and FeS-B and which encodes cytochrome P450SU2 and FeS-A wasobtained from S. griseolus mutant PH2001 and cloned using methods wellknown to those skilled in the art (Maniatis et al., Molecular Cloning: aLaboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y.).The 2.0 kb BamHI fragment was shown to encode both cytochrome P450SU2and FeS-A as determined by DNA sequence analysis of the DNA. The 2.0 kbBamHI DNA fragment was subcloned into the plasmid pUC19 in E. coli andis called pUC19-SU2-8 and has been deposited in the American TypeCulture collection and has ATCC accession number 67781. A restrictionendonuclease map of pUC19-SU2-8 is shown in FIG. 4.

The DNA sequence of cytochrome P450SU1 and FeS-B protein genes

By further restriction endonuclease mapping, it was determined that a2.0 kb SacI-BamHI fragment of DNA derived from the 2.4 kb BamHI fragmentin pUC18-SU1-BamHI contains the complete DNA coding sequence for thecytochrome P450SU1 and FeS-B proteins. That the 2.0 kb fragment containsthe complete DNA coding sequence for the cytochrome P450SU1 and FeS-Bproteins was determined by comparing all possible proteins encoded bythe DNA sequence of the fragment with the molecular weight, amino acidcomposition, and N-terminal amino acid sequences of P-450SUI and theamino acid composition of N-terminal amino acid sequence of FeS-B, asshown above. The DNA sequence of the 2.0 kb SacI-BamHI fragment wasdetermined from about 100 bp downstream of the SacI site through theBamHI site using methods well known to those skilled in the art(Messing, Methods in Enzymology 101: 20-78 (1983), herein incorporatedby reference), and is shown as follows with the coding sequences ofcytochrome P450SU1 and FeS-B, which start at base no. 128 and end atbase no. 1578, indicated.

DNA Sequence of the DNA Containing the Coding Sequences for CytochromeP450SU1 and FeS-B ##STR2##

DNA Sequence of the cytochrome P450SU2 and FeS-A protein genes

The DNA sequence of the 2.0 kb BamHI fragment isolated from S. griseolustransformed with the plasmid pUC19-SU2-8 that contains the genes forcytochrome P450SU2 and the iron sulfur protein FeS-A was determined bymethods well known to those skilled in the art and described by Messing,Methods in Enzymology 101: 20-78 (1983). That the 2.0 kb BamHI DNAfragment encodes cytochrome P450SU2 and FeS-A was determined bycomparing all possible proteins encoded by the DNA sequence to the knownsize, amino acid composition, and amino terminal amino acid sequence ofP450SU2 and the known amino acid composition and amino terminal aminoacid sequence of FeS-A. The DNA sequence of the fragment is shown asfollows and the locations of the coding sequence for cytochrome P450SU2and FeS-A, which start at base no. 195 and end at base no. 1646 areindicated.

DNA Sequence of the 2.0 kilobase BamHI DNA fragment Containing theCoding Sequences for Cytochrome P450SU2 and FeS-A ##STR3##

Plasmids for the constitutive expression of cytochrome P450SU1 in otherorganisms

Plasmids with which to transform other organisms to constitutivelyexpress cytochrome P450SU1 alone and P450SU1 and FeS-B together may bemade as follows. Expression of the two genes (i.e., the DNA sequences)may be driven by the promoter and transcription signal of the genes fromS. griseolus, or by any plasmid promoter(s) and translation signals thatallow constitutive expression of exogeneous coding sequences in theorganism to be transformed. The non-regulated expression of the genesfrom these promoters in other organisms as exemplified by the exampleherein, in S. lividans, and as opposed to their regulated expression inS. griseolus is presumably due to the absence of the regulatory factors(genes) in the other organisms that normally regulate the expression ofcytochrome P450SU1 and FeS-B in S. griseolus.

pCAO400

This plasmid was made in E. coli by inserting the 2.4 kb BamHI fragmentfrom pUC18-SU1-BamHI that contains the genes for both cytochrome P450SU1and FeS-B into the unique BamHI site of pCAO170 (Omer et al., J.Bacteriol. 170:2174-2184, (1988)), using methods described in Maniatiset al., Molecular Cloning: a Laboratory Manual, Cold Spring HarborPress, Cold Spring Harbor, N.Y. pp. 390-400. The plasmid pCAO170 in E.coli CE170 has been deposited in the American Type Culture Collectionand has the ATCC accession number 68085. The resulting plasmid is calledpCAO400.

pCAO401

This plasmid was made in E. coli by inserting the 2.0 kb BamHI-SacIfragment from pUC18-SU1-BamHI that contains the genes for bothcytochrome P450SU1 and FeS-B into pCAO170 that had been digested withBamHI and SacI restriction endonucleases using methods as described byManiatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y. The resulting plasmid is calledpCAO401.

pCAO200SU1-FeS-B #9

This plasmid was made similarly to the way pCAO400 above was made exceptthat pCAO200 which can be made from pCAO170 (Omer et al., J. Bacteriol.170:2174-2184, (1988)), was used instead of pCAO170 as the recipient ofthe 2.4 kb BamHI fragment.

pCAO200SU1#12

This plasmid was made by deleting the complete FeS-B protein codingsequence from the 2.4 kb BamHI DNA fragment. The deletion was made asdescribed (Henikoff, Gene, 28:351-359 (1984); Messing, Methods inEnzymology 101: 20-78 (1983)). The resulting 1.8 kb DNA fragment stillcontains the sequences upstream of SU1, the complete cytochrome P450SU1coding sequence, and 6 bp downstream of SU1. It is designatedpUC118-SU-1.8. A BamHI site containing linker was inserted at theHindIII site downstream of the P450SU1 coding region and the resultingfragment was inserted in pUC118 creating pUC118-SU1-1.8(B). The 1.8 kbBamHI DNA fragment was isolated from pUC118-SU1-1.8(B) and inserted intothe BamHI site of pCAO200 using methods well known to those skilled inthe art (Maniatis et al., Molecular Cloning: a Laboratory Manual, ColdSpring Harbor Press, Cold Spring Harbor, N.Y. pp 390-400) creating theplasmid pCAO200SU1#12.

Plasmid for the constitutive expression of cytochrome P450SU2 in otherorganisms

A plasmid for introducing the genes for cytochrome P450SU2 and FeS-Ainto S. lividans may be constructed as follows. The 2.0 kb BamHIfragment from pUC19-SU2-8 containing the genes for cytochrome P450SU2and FeS-A can be cloned into the BamHI site of pCAO200 using methodswell known to those skilled in the art creating pCAO200SU2-FeS-A#11(Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y., pp. 390-400). This fragment mayalso be cloned in other vectors.

The five plasmids, pCAO400, pCAO401 (FIGS. 3A and 3B), pCAO200SU1-FeS-B#9, pCAO200SU1#12 (FIGS. 4A and 4B), and pCAOSU2-FeS-A (FIG. 8) wereintroduced into S. lividans JI1326 as described by Hopwood et al.,Genetic Manipulation of Streptomyces. A Laboratory Manual, John InnesFoundation, Norwich, U.K., pp 108-109. S. lividans JI1326 has beendeposited in the American Type Culture Collection and has the ATCCaccession number 53939. Transformants were selected for thiostreptonresistance which is encoded on the plasmids. These plasmids, which arebased upon the SLP1 plasmid, site-specifically integrate into a uniquelocus in the S. lividans chromosome and are present in 1-2 copies perchromosome (Omer et al., J. Bacteriol. 170:2174-2184, (1988)).

While S. lividans can be transformed by the plasmids describe above(including pCAO200SU1-FeS-B#9, pCAOSU2-FeS-A#11, pCAO400 and pCAO401)the host range of these SLP1-derived plasmids is limited (Kieser et al.,1982, Mol. Gen. Genet. 185:223-238). Broad host range plasmids such asthose derived from the plasmids SCP2 or pIJ101 can be used to introduceinto and allow expression of these genes in other Streptomyces species(Lydiate et al., 1985, Gene 35:223-235, Kieser et al., 1982, Mol. Gen.Genet. 185:223-238, Ward et al., 1986, Mol. Gen. Genet. 203:468-478).The 2.4 kb BamHI DNA fragment from pUC18-SU1 BamHI that contains thegenes for P450SU1 and FeS-B can be cloned into the BamHI site of pIJ922using methods well known to those skilled in the art (Maniatis et al.,1982, A Guide to Molecular Cloning: A Laboratory Manual) creatingpPAT108 (FIG. 16A). The 2.0 kb BamHI DNA fragment from pUC19-SU2-8 canbe cloned into the BglII site of pIJ425 using methods well known tothose skilled in the art (Maniatis et al., 1982, A Guide to MolecularCloning: A Laboratory Manual) creating pCS325 (FIG. 16B). The plasmidspPAT108 and pCS325 can be transformed into various Streptomyces speciesand will enable the transformed strains to constitutively metabolizeherbicide chemicals.

Engineering plasmids with P450SU1 for the transformation of plants

For transcription and translation in plants, additional sequences mustbe added to the 5'-end and 3'-end of the DNA fragment comprising thecytochrome P450SU1 coding sequence. This yields a recombinant plasmidcomprising A) a DNA fragment of the 2.4 kb BamHI fragment encodingenzyme P450SU1, a DNA fragment of the 2.0 kb SacI-BamHI fragmentencoding enzyme P450SU1, a DNA fragment of the 1.8 kb BamHI fragmentencoding enzyme P450SU1, or the 2.0 kb BamHI fragment encoding P450SU2isolated from S. griseolus mutant PH2001; B) a DNA sequence of a plantpromoter upstream and operably linked to said fragment; C) a5'-untranslated sequence including a ribosomal binding site upstream andoperably linked to said fragment; D) a DNA sequence downstream andoperably linked to said fragment of a 3'-untranslated sequence whichenables the mRNA transcribed from the plasmids to be polyadenylated onits 3'end.

This can be done using standard genetic engineering techniques asdescribed in Maniatis et al., Molecular Cloning: a Laboratory Manual,Cold Spring Harbor Press, Cold Spring Harbor, N.Y. and Kunkel, T. A. etal. Proc. Natl. Acad. Sci. U.S.A., 82:488-492 (1985).

Sources for a DNA fragment encoding the P450SU1 gene product include a2.4 kb BamHI DNA fragment or a 2.0 kb BamHI-SacI DNA fragment frompUC18-SU1-BamHI. A source for a DNA fragment encoding the P450SU2 geneproduct is a 2.0 kb BamHI fragment in pUC19-SU2-8 isolated from S.griseolus mutant PH2001. A preferred source of a DNA fragment comprisingthe sequences encoding the P450SU1 gene product is the 2.4 kb BamHI DNAfragment from pUC18-SU1-BamHI. An alternative source for a similarcytochrome P450 gene would be the P450SU2 gene contained on a 2.0 kbBamHI fragment in pUC19-SU2-8.

Addition of promoter and 5'-untranslated sequences to the P450SU1 codingsequence

A plant promoter and 5'-untranslated sequence including a ribosomalbinding site must be added upstream of the DNA encoding cytochromeP450SU1 to permit the transcription and translation of the P450SU1 genein plants. Among the promoters and 5'-untranslated sequences that willsuffice for this purpose are those of the 35S promoter from theCauliflower Mosaic Virus (CaMV) (Harpster et al. Mol. Gen. Genet.212:182-190 (1988)), the light induced and tissue specific SSU301 genefrom petunia (Dean et al. Mol. Gen. Genet. 206:465-474 (1987)), thelight induced and tissue specific Cab22L gene from petunia (Dunsmuir,Nucleic Acids Res. 13:2503-2518 (1985) and Harpster et al. Mol. Gen.Genet. 212:182-190 (1988)), and the chemically inducible absicicacid-regulated Em promoter from wheat (Marcotte et al., The Plant Cell1:969-976 (1989)). Other plant promoters and 5'-untranslated regionsfrom plant genes could also be used.

Addition of 3'-untranslated sequences to the P450SU1 coding sequence

Sequences must be added downstream of the DNA encoding cytochromeP450SU1 to enable the mRNA transcribed from the vectors to bepolyadenylated on its 3'-end. A preferred source of such DNA is from theSSU301 gene from petunia (SSU301 encodes the small subunit of ribulosebisphosphate carboxylase) (Dean et al. Mol. Gen. Genet. 206:465-474(1987)). This provides a poly A addition site on the P450SU1 encodingmRNA transcript when the 3'-tail region from the SSU301 gene iscotranscribed along with the p450SU1 coding sequence. Other plant genescould be used as sources of these 3'-untranslated sequences.

Addition to the cytochrome P450SU1 coding sequence of sequences encodingpeptides that can facilitate the transport of cytochrome P450SU1 intothe chloroplast of the plant cell

Plasmids consisting of the plant promoter, plant 5'-untranslatedsequences, P450SU1 coding sequence, and plant 3'-untranslated sequenceswill express cytochrome P450SU1 in the cytoplasm of the plant cell.Localization of P450SU1 in chloroplasts instead of the cytoplasm maygive better metabolism of herbicides because in chloroplasts there areelectrons and iron-sulfur proteins that could deliver electrons toP450SU1 that might not be present in the cytoplasm. In order to expressthe cytochrome P450SU1 protein in the chloroplasts of plants,constructions require in addition to the above mentioned components atransit peptide encoding sequence fused to the cytochrome P450SU1sequence to direct the protein into the chloroplasts. Such sequences maybe engineered using coding regions of the transit peptide sequences, orcoding regions of the transit peptide sequence plus a portion of thecoding region of the mature polypeptide, of nuclear genes encodingproteins that are normally imported into the chloroplasts of plants.Good sources of sequences for these fusions are the ribulosebisphosphate carboxylase (SSU) (Dean et al. Mol. Gen. Genet. 206:465-474(1985)) and the chlorophyll a/b binding protein (Dunsmuir, Nucleic AcidRes. 13:2503-2518 (1985)) both from petunia. Other sources would besimilar, nuclear encoded genes from other plants that encode proteinsthat are transported into chloroplasts. Fusions that only add the aminoterminal amino acid sequence that is normally removed upon transportinto chloroplasts and fusions that contain the normally removed peptidesequence and up to at least 27 amino acids of the mature transportedprotein can be added onto the amino terminus of cytochrome P450SU1 anddownstream from the promoter and ribosomal binding site withoutpreventing the expression of functional P450SU1 protein.

This technique will work for introducing into plants any solublecytochrome P450 enzyme for which chloroplast ferredoxin acts as areductant.

Engineering plasmids with P450SU1 and FeS-B for the transformation ofplants

Although chloroplast ferredoxin are a source of reductant for cytochromeP450SU1, an alternative source is the FeS-B protein from S. griseoluswhich is the natural reductant for P450SU1. Thus plasmids that uponintroduction into plant cells can direct the expression of bothcytochrome P450SU1 and FeS-B are useful. To express both proteins inplant cells, modifications similar to those used to express cytochromeP450SU1 can also be done, on the same plasmid, to express FeS-B protein.Such proteins can be directed either to the cytoplasm or to chloroplastsof plant cells.

Such a recombinant plasmid resulting in expression in the cytoplasmcomprises A) the DNA encoding for the cytochrome P450 or the DNAencoding for the cytochrome P450 and the DNA encoding for the FeSprotein, B) one or more segments of the DNA sequence of a plant promoterupstream and operably linked to said encoding, C) one or more of a5'-untranslated sequence including a ribosomal binding site upstream andoperably linked to said encoding, and D) one or more of a DNA sequencedownstream and operably linked to said encodings of a 3'-untranslatedsequence which enables the mRNA transcribed from the plasmids to bepolyadenylated on its 3' end.

Alternatively, a plasmid for targetting the proteins to the chloroplastscomprises A) the DNA encoding for the cytochrome P450 and the DNAencoding for the FeS protein, B) one or more segments of the DNAsequence of a plant promoter operably linked to said encoding in theupstream position; C) one or more of a 5'-untranslated sequenceincluding a ribosomal binding site operably linked to said encoding inthe upstream position; D) one or more of a DNA sequence operably linkedto said encoding in the downstream position of a 3'-untranslatedsequence which enables the mRNA transcribed from the plasmids to bepolyadenylated on its 3' end; and E) one or more of a transit peptidecoding sequence or a transit peptide encoding sequence and additionallymature coding sequence of nuclear genes that encode proteins that arenormally imported into the chloroplasts of plants operably linked to theDNA encoding for the amino terminus of the cytochrome P450, or to theDNA encodings for the amino terminae of the cytochrome P450 and FeSprotein, and downstream from the promoter and ribosomal binding site.

The preferred plasmids for expression of cytochrome P450SU1 along withFeS-B in the cytoplasm and chloroplasts of plants cells are described inExample 19.

Introduction of plasmids into plants

DNAs containing the cytochrome P450SU1, P450SU2, FeS-A or FeS-B codingsequences with promoters from plant genes can be subcloned into T-DNAplasmids that mediate the transfer of these DNAs from Agrobacterium toplants (R. T. Fraley et al. Proc. Natl. Acad. Sci. U.S.A. 80:4803-4807(1983), H. Klee et al. Annual Rev. Plant Physiol. 38:476-486 (1987) andreferences therein). This subcloning can be performed by methods wellknown to those skilled in the art (T. Maniatis et al., MolecularCloning: a Laboratory Manual, Cold Spring Harbor Press, Cold SpringHarbor, N.Y. (1982) and T. A. Kunkel Proc. Natl. Acad. Sci. U.S.A.82:488-492 (1985)). Although several different T-DNA plasmids were usedin the examples presented here, pAGS502 could have been used for all ofthem since it contains unique HindIII, BamHI and EcoRI sites in theT-DNA region. Other T-DNA plasmids could also be used too as long assuitable restriction sites (i.e., HindIII, BamHI, EcoRI) are present inthe region of the plasmid that is mobilized into plant cells.Alternatively, the restriction sites on the DNA fragments to be insertedinto the T-DNA plasmids could be changed (T. A. Kunkel Proc. Natl. Acad.Sci. U.S.A. 82:488-492 (1985)) to allow insertion into most anyrestriction endonuclease site in a T-DNA plasmid.

Plasmids are mobilized into Agrobacterium such as A. tumifaciens strainLBA4404 (Hoekema et al. Nature 303:179-180, 1983) using tri-parentalmatings (Ruvkin and Ausubel, Nature 289:85-88, 1981), or the freeze-thawmethod (Plant Molec. Biol. Manual, S. B. Gelvin and R. A. Schilperoot,Eds., A3:1-19, 1988). The resulting Agrobacterium strains are thencocultivated with protoplasts as described by van der Elzen et al. PlantMol. Biol. 5:149-154(1985) or leaf disks as described by Horsch et al.Science 227:1229-1231, (1985) of Nicotiana tabacum cv. Wisconsin 38 andkanamycin resistant transformants selected. Kanamycin resistanttransformed tobacco plants are regenerated from the transformedprotoplasts or leaf disks and the plants are allowed to flower. Seed isobtained from each plant following self pollination.

Plants other than Nicotiana tabacum, including plants of horticulturalor agronomic utility, such as vegetable or other crops, can betransformed in ways known to those skilled in the art (Gasser andFraley, Science 244:1293-1299 (1989)). Using the Agrobacterium mediatedT-DNA transfer of DNA the plasmids pSU18, pSSU-SU111, pSSU-SU121,pCab-SU111, pCabSU121, pCab-SU131, pSuFe11, pSuFe21, pSuFe31 and pSuFe41can be mobilized into plant species that include, but are not limited toLycopersicon esculentum, (tomato), (McCormick et al., Plant Cell Rep.,5:81-84 (1986)), Brassica napus, (oilseed rape), (Pua et al.,Bio/Technology. 5:815-817 (1987)); Gossypium hirsutum, (cotton), (Umbecket al., Bio/Technology 5:263-266 (1987)) Glycine max, (soybean) (Hincheeet al., Bio/Technology, 6:915-921 (1988)), and Arabidopsis thaliana(Valvekens et al., Proc. Natl. Acad. Sci. U.S.A. 85:5536-5540 (1988)).The plasmids pSU18, pSSU-SU111, pSSU-SU121, pCab-SU111, pCabSU121,pCab-SU131, pSuFe11, pSuFe21, pSuFe31 and pSuFe41 can be transformedinto plant protoplasts as has been demonstrated for rice (Oryza sativa)(Toriyama et al., Bio/Technology, 6:1072-1074 (1988)) and maize (Zeamays L.) (Rhodes et al., Science, 140:204-207 (1988)). An additionalalternative method to introduce the plasmids pSU18, pSSU-SU111,pSSU-SU121, pCab-SU111, pCabSU121, pCab-SU131, pSuFe11, pSuFe21, pSuFe31and pSUFE41 into plants is through the use of a "particle gun" (Klein etal., Nature, 327:70-73 (1987)). This method has been shown to work forNicotiana tabacum, tobacco, (Klein et al., Proc. Natl. Acad. Sci.,U.S.A., 85:8502-8505 (1988)) and Glycine max, soybeans, (McCable et al.,Bio/Technology, 6:923-926 (1988)) but is not necessarily limited tothese species.

Following introduction of plasmids into plant cells by any of the aboveprocedures, the plasmids or portions of these plasmids may be stablyincorporated into the chromosomal DNA of the cell. In the case whereplants are regenerated from single cells, all cells of the regeneratedplant are expected to carry the integrated plasmid or plasmid parts. Inthe case where single cells within a regenerating multicellularstructure are transformed, cells arising from the transformed cell(s)will give rise to sectors which carry the integrated plasmid or plasmidparts. In either case, the regenerated plants carrying the plasmid orplasmid parts are termed primary transformants. Depending on thespecies, the primary transformants can flower and give rise to gameteswhich fuse to form zygotes either by self pollination or by outcrossingwith other plants of the same species.

Seed arising from either self pollination or outcrossing of a primarytransformant contain embryos which are progeny of the primarytransformant. A portion of the progeny plants may recieve chromosomeswhich carry copies of the plasmid or plasmid parts, depending on thenumber of copies of the plasmid or plasmid parts stably incorporated inthe primary transformant, patterns of mendelian segregation, linkagerelationships between the plasmids or plasmid parts where multiplecopies exist, and whether or not the gametes arose from sectors carryingthe integrated plasmid or plasmid parts. In like fashion these progenyplants may flower and give rise to subsequent generations of seed andplants carrying the plasmid or plasmid parts incorporated into theoriginal primary transformant.

A similar situation pertains to the endosperm tissue of seed in caseswhere the endosperm is formed by sexual means.

A male sterility system for hybrid seed production

A means of inducing male sterility in plants generating the femaleparent to be used in a cross to produce hybrid seed would be veryuseful. Hybrid seed production is an important means of introducingdesirable traits into agronomically valuable crop plants. For instance,quality traits such as oil content, herbicide resistance, diseaseresistance, adaptability to environmental conditions, and the like, canbe hybridized in offspring so that the latter are invested with the mostdesirable traits of its parents. In addition, progeny from a hybridcross may possess new qualities resulting from the combination of thetwo parental types, such as yield enhancement resulting from thephenomenon known as heterosis. Controlled cross-fertilization to producehybrid seeds has been difficult to achieve commercially due to competingself-fertilization, which occurs in most crop plants.

Currently, hybrid seed production is performed by one of the followingmeans: (a) mechanically removing or covering the male organs to preventself-fertilization followed by exposing the male-disabled plants toplants with male organs that contain the trait(s) desired for crossing;(b) growing genetically male-sterile plants in the presence of plantswith fertile male organs that contain the trait that is desired forcrossing; or (c) treating plants with chemical hybridizing agents (CHA)that selectively sterilize male organs followed by exposing themale-disabled plants to plants with fertile male organs that contain thetrait that is desired for crossing. Some disadvantages to each of thesemethods include: (a) this is only possible for a few crops, such ascorn; where the male and female organs are separate; and it is laborintensive and costly; (b) genetically male sterile lines are cumbersometo maintain, requiring crosses with restorer lines; (c) CHAs are nothighly effective. The following method is applicable to a wide range ofcrops and allows selfing to maintain lines.

A plant is made to be receptive to male sterility induction by theintroduction of the cytochrome p450SU1 or SU2 coding region undercontrol of a suitable male organ-specific promoter. The resultingtransgenic plant produces the cytochrome p450 enzyme only in its maleorgan. Such transgenic plants are male-fertile when grown normally. Thep450-containing untreated fertile plant can be genetically crossed andpropagated normally through seed production. Unlike normal plants,however, these plants can be rendered male-sterile by exposure tonontoxic chemical that is converted by the p450 enzyme into an activetoxin. The toxin present in the male organ disrupts normal pollendevelopment making the plant male sterile. The male sterility trait isonly expressed when wanted, by contacting the plant with a selectedprotoxin; otherwise the transgenic plant behaves normally. Suitableprotoxins include 10015 and other compounds that are sufficientlyconverted into 10014 by the cytochrome p450 enzyme.

EXAMPLES 1-3 Demonstration of constitutive expression of cytochromeP450SU1 in S. lividans strains that are transformed with pCAO400,pCAO401, pCAO200SU1-FeS-B#9 and pCAO200SU1#12

Cultures of S. lividans strains transformed with any one of the fourplasmids pCAO400, pCAO401, pCAO200SU1-FeS-B#9 and pCAO200SU1#12 weregrown in either sporulation broth or YEME broth media. The cultures weregrown for approximately 24-36 hours at 30° C. An aliquot of cells wasremoved from the cultures at this time. If sulfonylurea induction ofcytochrome P450SU1 was to be tested, a solution of the sulfonylurea10001 that gave a final concentration in the culture of approximately0.1-0.15 mg/ml was added to the culture remaining after the removal ofthe aliquots. Aliqouts of cells were removed from the induced culture atvarious intervals up to 24 hours later and harvested and washed asdescribed.

Western blot analyses for cytochrome P450SU 1 was performed on cellextracts as described.

EXAMPLE 1

S. lividans transformed with pCAO400 and S. lividans C37 (Omer et al.,J. Bacteriol. 170:2174-2184, (1988), herein incorporated by reference),which contains the plasmid pCAO106 (from which pCAO170 the plasmid fromwhich pCAO400 was derived), were grown as separate cultures insporulation broth as described above. An aliquot of cells was removedfrom each culture before adding 10001 to a concentration of 0.12 mg/mlto the cells and another aliquot of cells was taken 24 hours afteradding 10001. Western blots were run on approximately 25 μg of proteinfrom each aliquot of cells and analyzed for the presence of cytochromeP450SU1 by means of antiserum to cytochrome P450SU1 as described. Thedata in FIG. 5 show that S. lividans C37 (which does not contain thegene for cytochrome P450SU1) made no cytochrome P450SU1 whether or notit was induced with 10001. It also shows that cytochrome P450SU1 wasmade by S. lividans transformed with pCAO400 whether or not it had beeninduced with 10001.

EXAMPLE 2

S. lividans containing pCAO400 and S. lividans containing pCAO401 wereused separately to inoculate 200 ml of sporulation broth and grown forapproximately 36 hours. Fresh sporulation broth (100 ml) was added toeach culture and a 30 ml aliquot was removed from each. At this time 36mg of 10001 was added to each culture followed by the removal of 30 mlaliquots at 3, 6 and 24 hours. The cells in each aliquot were pelletedby means of centrifugation, washed and broken in a French pressure cell,as described. Approximately 25 μg of protein from each aliquot was usedin a Western blot analysis for cytochrome P450SU1 by means ofanti-P450SU1 antibody. The results shown in FIG. 6 indicate thatcytochrome P450SU1 was produced by both S. lividans containing pCAO400and S. lividans containing pCAO401, whether or not 10001 had been added.

EXAMPLE 3

S. lividans containing pCAO200, S. lividans containingpCAO200SU1-FeS-B#9 and S. lividans containing pCAO200SU1#12 were grownseparately in 400 ml of YEME broth with shaking at 30° C. forapproximately 36 hours. S. griseolus ATCC 11796 was grown in 400 ml ofsporulation broth for approximately 30 hours. Six hours beforeharvesting the cells from the cultures, 200 ml of YEME was added to theS. lividans cells. Six hours before harvesting, the S. griseolus culturewas split into two 200 ml aliquots and 100 ml of fresh sporulation brothwas added to each. At this time, 36 mg of 10001 was also added to one ofthe two S. griseolus cultures. The cells from each of the five cultureswere harvested by means of centrifugation and washed twice with 50 mMMOPS pH 7.2 and an aliquot of the harvested cells was broken in a Frenchpressure cell, as described. Approximately 30 μg of protein was used ina Western blot analysis for cytochrome P450SU1 using antiserum againstcytochrome P450SU1. The results are shown in FIG. 7. No cytochromeP450SU1 was found in the S. lividans cells containing pCAO200 or in theS. griseolus culture not induced with 10001. Cytochrome P450SU1 wasdetected in the cultures of S. lividans transformed with eitherpCAO200SU1-FeS-B#9 or pCAO200SU1#12 and in the S. griseolus ATCC 11796culture induced with 10001.

EXAMPLES 4-9 Metabolism of sulfonylurea compounds by S. lividans cellscontaining the genes for cytochrome P450SU 1 and FeS-B

EXAMPLE 4

Separate cultures (50 ml) inoculated with S. lividans C37, S. lividanstransformed with pCAO400 or S. lividans transformed with pCAO401 insporulation broth containing 0.12 mg/ml of 10001 were grown with shakingat 30° C. Aliquots (1.5 ml) of each culture were removed at 24, 32, 48and 56 hours after inoculation and the supernatant of each aliquot wasanalyzed by HPLC for its concentration of 10001 and its metabolites10002 or 10003.

The concentration (μM) of each compound is presented in Table 1.

                  TABLE 1                                                         ______________________________________                                                   Time                                                               Strain     (hours) 10001      10002 10003                                     ______________________________________                                        S. lividans                                                                               0      284         0     0                                        pCAO401    24      230        32    26                                                   32      203        44    36                                                   48      123        63    46                                                   56      105        71    48                                        S. lividans                                                                               0      300         0     0                                        pCAO400    24      269        17    16                                                   32      240        25    22                                                   48      184        39    28                                                   56      137        47    29                                        S. lividans                                                                               0      325         1     0                                        C37        24      320         2     0                                                   32      295         3     0                                                   48      281         6     3                                                   56      280         7     3                                        ______________________________________                                    

EXAMPLE 5

A 100 ml culture of S. griseolus ATCC 11796 in sporulation broth and a50 ml culture of S. lividans transformed with pCAO400 in YEME broth wereprepared and incubated for 24 hours as described. At that time, the S.griseolus culture was split into two 50 ml aliquots into two separateflasks and 25 ml of fresh sporulation broth was added to each and 9 mgof 10001 was added to one of these cultures to induce cytochrome P450SU1expression. Fresh YEME broth (25 ml) was added to the S. lividansculture. After an additional 6 hours growth at 30° C., the cells in eachculture were harvested as described above, washed twice with MOPS (50mM, pH 7.2) and recentrifuged. The cell pellets were resuspended in fourcell volumes of MOPS (50 mM, pH 7.2) containing 0.2% glucose and about100 μg/ml of 10004. These cell suspensions were incubated at 30° C. withshaking and aliquots were taken at 2 and 5.5 hours. The supernatant ofeach aliquot was analyzed by HPLC and the concentrations of thesulfonylurea compound 10004 and its metabolite 10005 were determined.

The concentration (μM) of 10004 and 10005 in the supernatant of eachaliquot is shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                   Time                                                               Cells      (hours)       10004  10005                                         ______________________________________                                        none       0             144     0                                            S. griseolus                                                                             2             55      72                                           uninduced  5.5           12     114                                           S. griseolus                                                                             2             0      122                                           induced    5.5           0      122                                           S. lividans                                                                              2             72      67                                           pCAO400    5.5           0      125                                           ______________________________________                                    

EXAMPLE 6

S. lividans transformed respectively with pCAO200SU1-FeS-B#9,pCAO200SU1#12 and pCAO200 were cultured for 36 hours in 400 ml of YEMEbroth at 30° C. S. griseolus ATCC 11796 was similarly cultured in 400 mlof sporulation broth. Six hours before harvesting the cells, 150 ml offresh YEME broth was added to the S. lividans cells, and the S.griseolus cells were split into two 200 ml cultures with 100 ml of freshsporulation broth added to each. 10001 (36 mg) was added to one of thetwo S. griseolus cultures to induce cytochrome P450SU1. The cells wereprepared as described above in Example 5 and the concentrations of thesulfonylurea compound 10006 and its metabolites 10007, 10008 or 10009were determined.

The concentration (μM) of each compound is presented in Table 3.

                  TABLE 3                                                         ______________________________________                                                   Time                                                               Cells      (hours)  10006   10007 10008 10009                                 ______________________________________                                        none       0        362     0     0     0                                     S. griseolus                                                                             2        404     1     1     1                                     ATCC 11796 4        394     2     1     1                                     uninduced  6        405     2     1     2                                     S. griseolus                                                                             2        369     4     3     4                                     ATCC 11796 4        357     6     6     7                                     induced    6        355     8     5     9                                     S. lividans                                                                              2        326     12    18    15                                    pCAO200    4        267     21    38    33                                    SU1-FeS-B#9                                                                              6        232     30    55    49                                    S. lividans                                                                              2        376     2     1     0                                     PCAO200SU1#12                                                                            4        384     2     1     1                                                6        386     2     1     1                                     S. lividans                                                                              2        381     4     0     0                                     pCAO200    4        377     1     0     0                                                6        375     1     0     0                                     ______________________________________                                    

EXAMPLE 7

The cells were prepared as described above for Example 6 and it wasdetermined to what extent the sulfonylurea compound 10010 wasmetabolized to compounds 10011 and 10012. The concentration (μM) of eachcompound is presented in Table 4.

                  TABLE 4                                                         ______________________________________                                                     Time                                                             Cells        (hours) 10010     10011 10012                                    ______________________________________                                        none         0       87         0    0                                        S. griseolus 2       70        12    0                                        ATCC11796    4       49        20    2                                        uninduced    6       37        24    8                                        S. griseolus 2       40        32    2                                        ATCC11796    4        8        46    11                                       induced      6        4        42    19                                       S. lividans  2       35        34    2                                        pCAO200      4       11        37    12                                       SU1-FeS-B#9  6        4        27    20                                       S. lividans  2       90         4    0                                        pCAO200      4       85         7    0                                        SU1#12       6       80        11    0                                        S. lividans  2       90         1    0                                        pCAO200      4       89         2    0                                                     6       89         3    0                                        ______________________________________                                    

EXAMPLE 8

The cells were prepared as described above for Example 6 and it wasdetermined to what extent the sulfonylurea compound 10001 wasmetabolized to compounds 10002 and 10003. The concentration (μM) of eachcompound is presented in Table 5.

                  TABLE 5                                                         ______________________________________                                                     Time                                                             Cells        (hours) 10001     10002 10003                                    ______________________________________                                        none         0       291       0     0                                        S. griseolus 2       244       20    14                                       ATCC 11796   4       167       54    37                                       uninduced    6        86       86    62                                       S. griseolus 2       220       127   76                                       ATCC 11796   4        36       203   128                                      induced      6        3        218   142                                      S. lividans  2        28       105   86                                       pCAO200      4        0        116   95                                       SU1-FeS-B#9  6        0        112   94                                       S. lividans  2       281       2     2                                        pCAO200      4       276       4     4                                        SU1#12       6       276       6     5                                        S. lividans  2       301       2     1                                        pCAO200      4       287       1     1                                                     6       313       2     2                                        ______________________________________                                    

EXAMPLE 9

The cells were prepared as described above for Example 6 and it wasdetermined to what extent the sulfonylurea compound 10004 wasmetabolized to compound 10005. The concentration (μM) of each compoundis presented in Table 6.

                  TABLE 6                                                         ______________________________________                                                     Time                                                             Cells        (hours)     10004   10005                                        ______________________________________                                        none         0           114      0                                           S. griseolus 2           52       68                                          ATCC 11796   4           0       114                                          uninduced    6           0       121                                          S. griseolus 2           0       122                                          ATCC 11796   4           0       120                                          induced      6           2       118                                          S. lividans  2           2        35                                          pCAO200      4           1       100                                          SU1-FeS-B#9  6           2       100                                          S. lividans  2           81       43                                          pCAO200      4           29       84                                          SU1#12       6           0       109                                          S. lividans  2           97       22                                          pCAO200      4           92       26                                                       6           85       30                                          ______________________________________                                    

Examples 4-9 demonstrate that the genes for cytochrome P450SU1 and FeS-Bwhen expressed in S. lividans can metabolize sulfonylurea compounds tothe same product that are produced by S. griseolus ATCC 11796.Expression in S. lividans strains that have the gene(s) for cytochromeP450SU1 with or without FeS-B, however, is constitutive, not requiringinduction by compounds like 10001. For optimal metabolic activity of S.lividans strains expressing cytochrome P450SU1, the gene for itselectron donor FeS-B must be present as well. Examples 6-9 demonstratethat expressing the genes for both P450SU1 and FeS-B in S. lividansenables S. lividans to metabolize several sulfonylurea compounds morereadily than S. griseolus cells that have not been previously inducedwith 10001. Such strains would be valuable for metabolizing sulfonylureacompounds that are poor inducers of cytochrome P450SU1 in S. griseolusATCC 11796 since they can be metabolized by the S. lividans strainsdescribed without having to first induce with 10001 or some othersulfonylurea and later remove the inducing compound and its metabolitesfrom the culture.

EXAMPLE 10 Constitutive expression of cytochrome P450SU2 and FeS-A in S.lividans

The plasmid made for the examples below was made by ligating the 2.0 kbBamHI fragment from pUC19-SU2-8 containing the genes for cytochromeP450SU2 and FeS-A into the BamHI site of pCAO200 which resulted in theplasmid pCAO200SU2-FeS-A#11. The plasmid pCAO200SU2-FeS-A#11 wastransformed into Streptomyces lividans using methods selecting forresistance to the antibiotic thiostrepton encoded by the plasmid(Hopwood et al., Genetic Manipulation of Streptomyces. A LaboratoryManual, pp. 12-14 and 104-109, John Innes Foundation, Norwich, U.K.,herein incorporated by reference). A restriction endonuclease map ofpCAO200SU2-FeS-A#11 is shown in FIG. 8.

S. lividans containing the plasmid pCAO200SU2-FeS-A#11 was grown in YEMEbroth at 30° C. as described in Example 1 and the level of cytochromeP450SU2 was analyzed by Western blot as in Examples 1-3. The results areshown in FIG. 9. As can be seen, cytochrome P450SU2 is expressed in S.lividans transformed with pCAO200-SU2-FeS-A in the absence ofsulfonylurea induction. S. lividans cells transformed with pCAO200 donot produce cytochrome P450SU2.

EXAMPLES 11-12 Metabolism of sulfonylurea compounds by S. lividans cellscontaining the genes for cytochrome P450SU2 and FeS-A EXAMPLE 11

S. lividans transformed with pCAO200SU2-FeS-A#11 and S. lividanstransformed with pCAO200 were cultured for 36 hours in 400 ml of YEMEbroth at 30° C. S. griseolus PH2001 (mutant without SU1) was cultured in400 ml of sporulation broth at 30° C. Nine hours before harvesting thecells, the S. griseolus PH2001 culture was divided into two 200 mlcultures. Both received 100 ml of fresh sporulation broth and onereceived 36 mg of 10001 to induce cytochrome P450SU2. The cells wereprepared as described above in Example 6 and the concentrations of thesulfonylurea compound 10001 and its metabolites 10002 and 10003 weredetermined.

The concentration (μM) of each compound is presented in Table 7.

                  TABLE 7                                                         ______________________________________                                                      Time                                                            Strain        (hours) 10001     10002                                                                              10003                                    ______________________________________                                        none          0       279        0   0                                        S. griseolus  2       271        7   1                                        PH2001        4       264       12   2                                        uninduced     6       244       23   3                                        S. griseolus  2       286       41   7                                        PH2001        4       256       60   10                                       induced       6       234       71   13                                       S. lividans   2       279        7   1                                        pCAO200SU2    4       273       12   2                                        --FeS-A#11    6       251       15   3                                        ______________________________________                                    

EXAMPLE 12

The cells were prepared as described above for Example 11 and it wasdetermined to what extent the sulfonylurea compound 10010 wasmetabolized to compound 10011.

The concentration (μM) of each compound is presented in Table 8.

                  TABLE 8                                                         ______________________________________                                                      Time                                                            Strain        (hours)     10010  10011                                        ______________________________________                                        none          0           88     0                                            S. griseolus  2           89     0                                            PH2001        4           88     0                                            uninduced     6           89     1                                            S. griseolus  2           64     21                                           PH2001        4           56     28                                           induced       6           50     32                                           S. lividans + 2           90     1                                            pCAO200SU2    4           84     5                                            --FeS-A#11    6           72     14                                           ______________________________________                                    

The results of Example 10 (the Western blot analysis) showed thatbacteria containing the cytochrome P450SU2 gene produced cytochromeP450SU2 constitutively. This is in contrast to the case in S. griseolusstrains in which P450SU2 is made in detectable amounts only with theaddition of inducing sulfonylurea compounds such as 10001 (O'Keefe etal. Recent Adv. in Phytochemistry 21: 151-137, (1987)). Results fromExamples 11 and 12 (the metabolism experiments) show that constitutiveexpression of the cytochrome P450SU2 and FeS-A genes in S. lividansenables S. lividans to metabolize sulfonylurea compounds nearly to thesame extent as S. griseolus PH2001. Also, S. lividans transformed withpCAO200SU2-FeS-A#11 metabolizes the sulfonylurea 10010, which is a poorinducer of cytochrome P450SU2 in S. griseolus, more readily thanuninduced S. griseolus PH2001.

EXAMPLE 13 Prevention of sulfonylurea inhibition of plant growth

A 2 liter culture of S. lividans pCAO200SU1-FeS-B#9 was grown in YEMEmedium at 30° C. until the culture was in late log phase of growth andthe absorbance in a spectrophotometer at a wavelength of 600 nM wasbetween about 1.0 and 1.3. Tomato seedlings (Lysopersicon esculentum cv."Pixie") were seeded directly onto soilless media, Oasis Wedges®(Smithers-Oasis, Kent, Ohio), fertilized with 500 ppm Peters'®fertilizer (20:19:18); and 300 ppm of iron was added weekly. As thetomato plants develop, roots ramify through the Oasis Wedges®. Thetomato plants were transplanted to pots when they were 4 inches tall asfollows.

Five inch standard round pots (without holes) were filled with Sassafrassandy loam (pH 6.7, 0.8% OM) and an oasis cube. The contents of the eachpot was sprayed, prior to transplanting the tomato plants, with either10001, in 25% dry flowable composition (25 DF) or 10010, 75 DF at ratesof 16, 32, 64, 125 or 250 grams of active ingredient per hectare (gai/ha). The Oasis cube was then removed and replaced by anothercontaining a transplant tomato plant dipped in either water (treatmentA), YEME medium (treatment B) or the culture of S. lividanspCAO200SU1-FeS-B#9 described above (treatment C). Six transplant tomatoplants received each of the three treatments, and five transplant tomatoplants (to serve as controls) received no treatment. The resultingtomato plants were grown in a greenhouse for 19 days and watered twicedaily, after which they were evaluated for visual injury (100=completekill, other numbers=percentage of injury relative to controls[subjectively determined], 0=no injury) with respect to the waterdipped, no-herbicide control treatments. The plants were left in thegreenhouse for one more week after which the fresh weights of the shootsof the plants were determined. The roots of the plants which receivedthese treatments and controls were examined too.

Table 9 shows the visual injury ratings for the transplants which weredetermined by visual inspection 19 days after transplanting (DAT).Tomato plant which were planted into 10001 and 10010 showed differentdegrees of visual damage depending on which treatment they received.Tomato plants treated with treatment C were significantly less injuredby 10001 when the latter was applied at rates of 64, 125, and 250 gai/ha than were the tomato plants which received treatments A or B.Tomato plants which had been transplanted into 10010 were injured tosimilar extents regardless of the treatment they received.

Weights of the fresh shoots of those plants which received 16 and 32 gai/ha of 10010 and of all those plants which received 10001 weredetermined (Table 10). The weights of the fresh shoots of tomatoesplanted into 10010 receiving water, YEME or S. lividans treatments werenot significantly different (p=0.05) from each other and were allconsiderably less than those which did not receive any herbicide. Whilethe shoots of tomatoes planted into 10001 (at application rates of 64,125, or 250 g ai/ha) weighed considerably less than those which did notreceive herbicide, they weighed significantly more when they had beendipped in S. lividans than when they were treated with water or YEME.Shoot weights of the tomatoes dipped in the cultures ofpCAO200SU1-FeS-B#9 were approximately 3-4 times greater at theconcentration of 250 g ai/ha of 10001 and 2-3 times at the concentrationof 125 g ai/ha of 10001. The differences between the weights of theshoots from plants which received 10001 at application rates of 16 or 32g ai/ha were not significant regardless of which additional treatmentthey received.

Visual examination of the root systems of selected treatments showed nosigns of injury when the plants were dipped in water, YEME orpCAO200SU1-FeS-B#9 and did not receive herbicide. Apparently, S.lividans produced no gross signs of damage or aberrant morphology to theroots. When the plants received 10001, they all had roots with damagetypical of that resulting from contact with sulfonylurea (stuntedprimary roots with poorly developed secondary roots). Presumably,dipping the plants in S. lividans depleted the level of 10001 in thesoil solution in the vicinity of the roots to a low enough level toalleviate some shoot symptoms, but not enough to mitigate damage to theroots directly in contact with the soil.

                  TABLE 9                                                         ______________________________________                                        Sul-  Dosage                       Treatment C                                fonyl-                                                                              rate     Treatment A                                                                              Treatment B                                                                            (pCAO200SU1-                               urea  (g ai/ha)                                                                              (water)    (YEME)   --FeS-B#9)                                 ______________________________________                                        Visual Injury Ratings of Transplanted Tomatoes*                               10010 250      100, 80, 100,                                                                            100, 80, 80,                                                                           70, 80, 80,                                               80, 100, 100                                                                             100, 80, 80                                                                            100, 90, 90                                      125      80, 100, 80,                                                                             100, 70, 80,                                                                           80, 80, 80                                                90, 100, 100                                                                             100, 80, 70                                                                            60, 80, 80                                       64       80, 100, 80,                                                                             50, 60, 80,                                                                            60, 100, 100                                              80, 100, 100                                                                             70, 100, 80                                                                            80, 80, 100                                      32       80, 100, 80,                                                                             70, 70, 60,                                                                            60, 50, 60                                                100, 100, 100                                                                            80, 60, 60                                                                             50, 60, 60                                       16       60, 80, 90,                                                                              60, 80, 70,                                                                            60, 60, 60                                                60, 50, 80,                                                                              80, 60, 50                                                                             60, 60, 60                                 10001 250      100, 80, 100,                                                                            80, 70, 80,                                                                            50, 50, 50                                                100, 90, 80                                                                              80, 100, 80                                                                            50, 50, 50                                       125      100, 100, 90,                                                                            70, 70, 70,                                                                            50, 50, 50                                                90, 80, 80 70, 80, 60                                                                             50, 50, 50                                       64       70, 50, 80,                                                                              60, 60, 80,                                                                            40, 50, 50                                                70, 70, 60 60, 60, 60                                                                             40, 40, 40                                       32       40, 100, 70,                                                                             50, 60, 50,                                                                            40, 40, 40                                                60, 80, 60 50, 80, 60                                                                             100, 40, 40                                      16       40, 40, 40,                                                                              60, 50, 50,                                                                            40, 40, 40                                                60, 40, 40 50, 50, 50                                                                             40, 40, 40                                 none   0       0, 0, 0    0, 0, 0, 0, 0, 0                                                   0, 0,      30, 30   20, 20                                     Mean value of visual ratings                                                  100010                                                                              250      95.0       86.7     65                                               125      91.7       83.3     76.7                                             64       90.0       83.3     86.7                                             32       93.3       66.7     56.7                                             16       70.0       63.3     60                                         10001 250      91.7       81.7     50.0                                             125      90         70       50                                               64       66.7       63.3     43.3                                             32       68.3       58.3     50                                               16       43.3       51.7     40                                         none           0          12       8                                          ______________________________________                                         *Scale of 0 to 100 with 100 = complete kill, 0 = no injury.              

                                      TABLE 10                                    __________________________________________________________________________           Dosage rate                  Treatment C (pCAO200SU1-                  Sulfonylurea                                                                         (g ai/ha)                                                                            Treatment A (water)                                                                      Treatment B (YEME)                                                                       --FeS-B#9)                                __________________________________________________________________________    Shoot Fresh Weights of Selected Treatments (grams)                            10010  32     0.85, 0.38, 0.93                                                                         3.0, 1.03, 1.05                                                                          2.16, 1.09, 2.30                                        0.74, 0.34, 0.66                                                                         1.74, 1.82, 0.98                                                                         2.21, 0.93, 2.07                                 16     0.56, 1.45, 2.54                                                                         1.42, 3.10, 1.65                                                                         2.86, 1.19, 3.27                                        2.14, 0.78, 0.18                                                                         1.56, 1.49, 0.28                                                                         2.70, 1.62, 0.95                          10001  250    0.53, 1.03, 0.46                                                                         0.64, 0.76, 0.51                                                                         2.64, 2.61, 2.50                                        0.10, 1.55, 0.10                                                                         0.19, 0.11, 0.20                                                                         2.17, 2.71, 1.81                                 125    1.86, 0.73, 1.88                                                                         1.13, 1.24, 1.68                                                                         3.06, 3.69, 4.00                                        0.1, 0.10, 0.10                                                                          0.63, 1.11, 0.58                                                                         1.41, 1.55, 2.60                                 64     2.06, 0.32, 1.45                                                                         1.32, 1.48, 2.23                                                                         4.04, 3.88, 2.74                                        0.78, 2.59, 1.04                                                                         0.62, 1.40, 1.36                                                                         2.91, 2.62, 1.45                                 32     2.43, 3.30, 1.16                                                                         0.53, 2.82, 1.86                                                                         4.02, 2.19, 3.22                                        5.36, 0.80, 1.90                                                                         1.26, 1.84, 2.26                                                                         4.10, 3.10, 3.59                                 16     3.85, 1.46, 4.80                                                                         3.61, 1.59, 2.62                                                                         2.60, 2.42, 2.36                                        3.79, 2.36, 3.23                                                                         1.77, 2.89, 1.59                                                                         4.32, 3.10, 3.80                          none          14.8, 17.1, 12.6                                                                         16.9, 15.0, 5.0                                                                          11.2, 12.09,                                            16.28, 14.77                                                                             11.4, 16.5 15.75, 7.8, 7.54                          Mean Shoot Fresh Weights (grams)                                              10010  32     0.65       1.60       1.79                                             16     1.28       1.58       2.10                                      10001  250    0.63       0.40       2.41                                             125    0.80       1.06       2.72                                             64     1.37       1.40       2.94                                             32     2.49       1.76       3.37                                             16     3.25       2.35       3.1                                       None          15.11      12.96      10.88                                     __________________________________________________________________________

EXAMPLE 14 Demonstration of metabolism of sulfonylurea compounds by S.griseolus, S. griseus, S. ambofaciens, and S. lividans that aretransformed with pPAT108

S. griseolus PH2003, S. griseus PH4001, S. ambofaciens PH4002, and S.lividans JI1326 were transformed with the plasmid pPAT108. Thetransformed S. griseolus strain, PH3826, was cultured for 24 hours in150 ml of sporulation broth with 5 ug/ml thiostrepton. The transformedS. griseus strain, PH3832, and the transformed S. ambofaciens strain,PH3834, were cultured for 24 hours in 150 ml of trypticase soy brothwith 5 ug/ml thiostrepton. The transformed S. lividans strain, PH3822,was similarly cultured in 150 mls of YEME broth with 5 ug/mlthiostrepton. Three hours before harvesting the cells, 50 ml of freshmedium of the same type with 5 ug/ml thiostrepton was added to eachculture. The cells from each of the cultures were harvested bycentrifugation, washed twice with 50 mM MOPS, pH 7.2 and resuspended infive cell volumes of MOPS and containing 0.2% glucose and 120 ug/ml ofthe sulfonylurea 10001. The cell suspensions were incubated at 30° C.with shaking and aliquots were removed at 0.5, 1, 2 and 4 hours. Thesupernatant of each aliquot was analyzed by HPLC and the concentrationof the sulfonylurea compound 10001 and its metabolites 10002 and 10003were determined.

The concentration (μM) of each compound is presented in Table 11.

                  TABLE 11                                                        ______________________________________                                                     Time                                                             Strain       (hours) 10001     10002                                                                              10003                                     ______________________________________                                        S. griseolus 0.5     222       41   22                                        PH3826       1.0     137       101  58                                                     2.0      19       171  97                                                     4.0      0        189  107                                       S. griseus   0.5     281       18   9                                         PH3832       1.0     238       45   26                                                     2.0     177       82   46                                                     4.0      77       138  80                                        S. ambofaciens                                                                             0.5     299        6   1                                         PH3834       1.0     278       11   6                                                      2.0     250       27   14                                                     4.0     191       64   33                                        S. lividans  0.5     294        2   1                                         PH3822       1.0     284        5   3                                                      2.0     262       10   5                                                      4.0     232       25   15                                        S. griseus   1.0     370        1   1                                         PH4001       4.0     377        2   4                                         S. ambofaciens                                                                             1.0     406        0   0                                         PH4002       4.0     412        0   0                                         ______________________________________                                    

EXAMPLE 15 Demonstration of metabolism of sulfonylurea compounds of S.griseolus, S. griseus, S. ambofaciens, and S. lividans strains that aretransformed with pCS325

S. griseolus PH2003, S. griseus PH40001, S. ambofaciens PH4002, and S.lividans JI1326 were transformed with the plasmid pCS325. Cells of thetransformed strains of S. griseolus PH3809, S. griseus PH3817, S.ambofaciens PH3818, and S. lividans PH3816, were grown and treated asdescribed in Example 14, and the concentrations of the sulfonylureacompound 10001 and its metabolites 10002 and 10003 were determined.

The concentration (μM) of each compound is presented in Table 12.

                  TABLE 12                                                        ______________________________________                                                     Time                                                             Strain       (hours) 10001     10002                                                                              10003                                     ______________________________________                                        S. griseolus 0.5     175       64   6                                         PH3809       1.0     108       155  16                                                     2.0      0        236  24                                                     4.0      0        238  25                                        S. griseus   0.5     226       37   3                                         PH3817       1.0     181       73   7                                                      2.0      69       167  16                                                     4.0      0        220  23                                        S. ambofaciens                                                                             0.5     286       16   1                                         PH3818       1.0     265       33   3                                                      2.0     210       67   7                                                      4.0     129       134  13                                        S. lividans  0.5     331       19   1                                         PH3816       1.0     339       36   3                                                      2.0     299       68   7                                                      4.0     248       103  11                                        ______________________________________                                    

The results in Examples 14 and 15 showed that transformation ofStreptomyces strains with broad host range plasmids containing the genesfor P450SU1 and FeS-B or P450SU2 and FeS-A enabled these transformedstrains to constitutively metabolize sulfonylurea compounds. The rate atwhich these transformed strains were able to carry out the metabolism ofa sulfonylurea compound varied depending on the ability of endogenousreductases to provide reducing equivalents to the P450 as required forcatalysis and on the copy number of the plasmid in the transformedstrain.

EXAMPLE 16 Metabolism of Non-sulfonylurea Herbicides by BacteriaContaining the Genes for P450SU1 or P450SU2

Separate cultures (50 ml) inoculated with S. lividans C37, S. lividanstransformed with pCAO200SU1-FeS-B#9, S. griseolus ATCC11796, S.griseolus PH2003 transformed with pIJ425, or S. griseolus PH2003transformed with pCS325 were cultured in sporulation broth for 18 hoursat 30° C. with shaking. Each culture was then resuspended in 25 ml freshsporulation broth and 3.0 mg herbicide added. In the case of cultures ofS. griseolus ATCC11796, a second culture containing herbicide and 3.0 mg10001 was also prepared. Each culture was reincubated for 24 hours, thenan aliquot of the medium was withdrawn and analyzed by HPLC. The percentconversion of herbicide was determined.

The percent conversion of herbicide is presented in Table 13. Theresults in Table 13 show that bacteria containing constitutivelyexpressed P450SU1 metabolized the nonsulfonylurea herbicides 10017,10018, and 10019. In addition bacteria containing constitutivelyexpressed P450SU2 metabolized, the nonsulfonylurea herbicides 10020,10021, 10017, 10022 and 10018.

                  TABLE 13                                                        ______________________________________                                        Percent Conversion                                                            Strain   10020  10021  10017                                                                              10022                                                                              10018                                                                              10019                                                                              10023                                                                              10001                         ______________________________________                                        S. griseolus                                                                           12     NT      1    1   NT*  0    0    100                           ATCC 17796                                                                    S. griseolus                                                                           33     NT     35   30   NT*  80   0    100                           ATCC 11796,                                                                   10001 added                                                                   S. lividans                                                                            17      0     19   50    0   0    0     0                            C37                                                                           S. lividans                                                                            19     23     47   42   56   35   0     56                           pCAO200                                                                       SU1-FeS-                                                                      B#9                                                                           S. griseolus                                                                            7      7      6    0   10   0    NT*  100                           PH2003                                                                        pIJ425                                                                        S. griseolus                                                                           89     93     98   96   72   9    NT*  100                           PH2003                                                                        pCS325                                                                        ______________________________________                                         *NT = Not tested                                                         

EXAMPLE 17 Metabolism of 10015 Analogs to 10014--Formation of PhytotoxicMetabolites by P450SU1

Cultures of S. griseolus ATCC11796 were cultivated in sporulation broth(50 ml) at 30° C. with shaking for 17 hours. Each culture was thenresuspended in 25 ml fresh sporulation broth, 3.0 mg sulfonylurea wasadded, and the culture reincubated for 4 days. Aliquots of the mediumwere then analyzed by HPLC. Formation of 10014 was measured based onsimilarity of retention time and UV spectrum of the test metabolite tothat formed by metabolism of 10015.

The percent conversion of sulfonylurea to 10014 is presented in Table14. The results in Table 14 show that P450SU1 metabolized thenonphytotoxic sulfonylureas 10015, 10024, 10025, 10026, 10027 and 10028to phytotoxic 10014.

                  TABLE 14                                                        ______________________________________                                                                  % Conversion                                        Sulfonylurea                                                                              N-substitution                                                                              to 10014                                            ______________________________________                                        10029       --CH.sub.3    0                                                   10024       --CH.sub.2 CH.sub.3                                                                         69                                                  10027       --CH.sub.2 CH.sub.2 CH.sub.3                                                                <10                                                 10004       --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3                                                       0                                                   10015       --CH(CH.sub.3).sub.2                                                                        100                                                 10030       --CH.sub.2 CH(CH.sub.3).sub.2                                                               0                                                   10025                                                                         benzyl      50                                                                10028       --CH.sub.2 CH═CH.sub.2                                                                  27                                                  10031       --COCH.sub.3  0                                                   10026       --CH.sub.2 CH.sub.2 F                                                                       18                                                  10032       --CH.sub.2 Si(CH.sub.3).sub.3                                                               0                                                   ______________________________________                                    

EXAMPLE 18 Prevention of sulfonylurea inhibition of plant growth

One liter cultures of S. griseolus ATCC 11796, S. lividans pCAO200, S.lividans pCAO200-#9-SU1-FeS-B or S. lividans pCAO200-#12-SU1 were grownin YEME medium (sporulation broth for the S. griseolus culture) at 30°C. until the cultures were in late log phase of growth and theabsorbance of each culture in a spectrophotometer at a wavelength of 600nM was between 1.0 and 1.3. Tomato seedlings (Lycopersicon esculentumcv. "Pixie") were seeded directly into soiless media, Oasis Wedges®(Smithers-Oasis, Kent, Ohio), fertilized with 500 ppm Peter's®fertilizer (20:19:18); and 300 ppm of iron was added weekly. As thetomato plants develop, roots ramify through the Oasis Wedges®. Thetomato plants were transplanted to pots when they were 4 inches tall asfollows.

Five inch standard round pots (without holes) were filled with Sassafrassandy loam (ph 6.7, 0.8% OM) and a single Oasis cube and then treatedpreemergence with either Classic® (10001) 25 DF (16, 32, 64, 125 and 250grams active ingredient/hectare [g ai/ha]) or Oust® (10010) 75 DF atrates of 4, 8, 16, 32 and 64 g ai/ha), both herbicides available fromE.I. du Pont de Nemours and Company, Wilmington, Del. The oasis cube wasthen removed and replaced by a transplant tomato dipped in either thecultures described above of S. griseolus ATCC 11796 (treatment A), S.lividans pCAO200 (treatment B), S. lividans pCAO200-#9-SU1-FeS-B(treatment C), S. lividans pCAO200-#12-SU1 (treatment D) or into water(treatment E). Five transplants were tested for each treatment at eachdosage rate. The pots were placed on a greenhouse bench for 22 days andwatered twice daily, after which shoot fresh weights of treatments weredetermined. Roots of these treatments and controls were examined too.Plants, soil and pots treated with bacterial cultures were double baggedand disposed by incineration.

Table 15 shows the weights of the fresh shoots for the transplants whichwere determined 22 days after transplanting. When fresh weights werecompared, the safening by treatment C (S. lividans-#9-SU1-FeS-B) wasclear (P=0.05). Treatment C permitted significantly greater freshweights than the water controls (treatment E) at 10001 rates of 32, 64and 125 g ai/ha and at 10010 rates of 16 and 32 g ai/ha. At theseherbicide application rates, treatment C gave greater safening thantreatments A, B and D as well, which demonstrated the need for theinclusion of the DNA encoding FeS-B for the best safening. Shoot freshweight of the tomatoes in treatment C (S. lividans pCAO200-#9-SU1-FeS-B)were approximately 2-3 times greater than those from the othertreatments when planted into soil with 32, 64 and 125 g ai/ha of 10001or 16 and 32 g ai/ha of 10010. The differences between the weights ofthe shoots from plants receiving the other herbicide treatments were notsignificantly different from those treated with water.

Visual examination of the root systems of the plants treated with any ofthe five treatments showed no signs of injury when they did not receiveherbicide. When the plants were treated with herbicide, all had rootswith damage typical of that resulting from contact with sulfonylureas(stunted primary roots with poorly developed secondary roots). Thispointed to S. lividans expressing the genes for cytochrome P450SU1 andFeS-B being able to deplete the level of herbicide within thetransplanted cube, but since S. lividans probably did not colonize theroots of the transplant, damage still occurred when the roots camedirectly in contact with the treated soil.

                  TABLE 15                                                        ______________________________________                                        Shoot Fresh Weights of Tomatoes Transplanted                                  into 10001 or 10010 after Various Treatments*                                         Rate     Pretreatment**                                               Herbicide                                                                             (g ai/ha)                                                                              A       B     C     D     E                                  ______________________________________                                        10001   16       0.88    0.67  1.63  0.62  1.67                                                (0.16)  (0.09)                                                                              (0.18)                                                                              (0.13)                                                                              (0.48)                                     32       0.74    0.47  1.62  0.82  1.07                                                (0.20)  (0.05)                                                                              (0.15)                                                                              (0.19)                                                                              (0.25)                                     64       0.21    0.53  1.24  0.47  0.46                                                (0.04)  (0.07)                                                                              (0.08)                                                                              (0.04)                                                                              (0.16)                                     125      0.49    0.38  1.01  0.35  0.23                                                (0.13)  (0.11)                                                                              (0.29)                                                                              (0.05)                                                                              (0.02)                                     250      0.44    0.25  0.55  0.26  (0.21)                                              (0.12)  (0.07)                                                                              (0.24)                                                                              (0.03)                                                                              (0.04)                             10010    4       1.16    0.73  0.88  0.88  2.00                                                (0.11)  (0.14)                                                                              (0.12)                                                                              (0.27)                                                                              (0.24)                                      8       0.58    0.69  1.02  0.75  0.65                                                (0.17)  (0.13)                                                                              (0.32)                                                                              (0.15)                                                                              (0.32)                                     16       0.32    0.65  0.98  0.56  0.39                                                (0.06)  (0.15)                                                                              (0.13)                                                                              (0.11)                                                                              (0.25)                                     32       0.33    0.42  1.01  0.62  0.28                                                (0.03)  (0.09)                                                                              (0.15)                                                                              (0.10)                                                                              (0.04)                                     64       0.30    0.39  0.46  0.29  0.34                                                (0.06)  (0.12)                                                                              (0.14)                                                                              (0.05)                                                                              (0.09)                             None    --       14.14   9.73  14.25 16.40 23.73                                               (0.44)  (1.90)                                                                              (2.56)                                                                              (2.91)                                                                              (4.70)                             ______________________________________                                         *The values in grams are the mean of five plants for each pretreatment an     herbicide rate. The standard deviation in parentheses () is indicated         below the mean weight value                                                   **Key to Pretreatments:                                                       A: Streptomyces griseoius ATTCC11796                                          B: Streptomyces lividans pCAO200                                              C: S. lividans pCAO200#9SU1-FeS-B                                             D: S. lividans pCAO200#12SU1                                                  E: water                                                                 

EXAMPLE 19 Engineering plasmids with the P450SU1 and or FeS-B codingsequences for the transformation of plants

Sequences must be added to 5'-end and 3'-end of the cytochrome P450SU1and FeS-B coding sequence in order to get transcription and translationof the cytochrome P450SU1 and FeS-B genes in plants. We have done so inten plasmids that are described below. General descriptions of these tenplasmids are given first followed by detailed descriptions of how theseplasmids were made.

A. Plasmid for cytoplasmic expression of cytochrome P450SU1 with orwithout FeS-B

The plasmid, pSU17, was prepared containing the P450SU1 coding sequencewith the Cauliflower Mosaic Virus 35S promoter and the 5' untranslatedregion from the petunia chlorophyll a/b binding protein gene "Cab22L"(described in Harpster et al. Mol. Gen. Genet. 212:182-190 (1988) hereinincorporated by reference) upstream of the P450SU1 coding sequence. The3' untranslated region from the small subunit of ribulose bisphosphatecarboxylase (SSU) gene "SSU301" from petunia (Dean et al. Mol. Gen.Genet. 206:465-474 (1987)) was placed downstream of the P450SU1 codingsequence. For propagation in E. coli the pSU17 contained the sequencesof the plasmid pUC118. A diagram of pSU17 is shown in FIG. 10A. Theconstruct pSU17 when introduced into plant cells expressed cytochromeP450SU1 in the cytoplasm.

The plasmid pSuFe1 contains two adjacent Cauliflower Mosaic Virus (CaMV)35S promoters promoting transcription in opposite directions along withthe 60 bp region from the 5'-untranslated region of the small subunit ofribulose bis-phosphate carboxylase (SSU) from petunia to constitutivelyexpress cytochrome P450SU1 and FeS-B in the cytoplasm of plants. The3'-untranslated region used for expression of both genes is from thegene for nopaline synthetase(nos) derived from T-DNA of Agrobacteriumtumefaciens (Depicker et al., J. Mol. Appl. Genet. 1:561-573 (1982)). Adiagram of pSuFe1 is shown in FIG. 15A.

B. Plasmids that encode cytochrome P450SU1 and or FeS-B proteins thatadditionally contain peptides that can facilitate the transport ofcytochrome P450SU1 or FeS-B into chloroplasts of plant cells

In order to express the cytochrome P450SU1 or FeS-B proteins in thechloroplasts of plants, eight constructions were engineered using 5'promoter regions, coding regions of the transit peptide sequences and insome cases part of the mature coding sequences of genes encodingproteins normally imported into the chloroplasts of plants. The genesfor normally imported proteins were those for ribulose bisphosphatecarboxylase (SSU) and chlorophyll a/b binding protein (Cab) both frompetunia. Plasmids that only added to the P450SU1 coding sequence theamino terminal amino acid sequence that is normally removed upontransport into chloroplasts and plasmids that added to the P450SU1coding sequence the normally removed peptide and up to 27 amino acids ofthe mature transported protein were constructed. Plasmids thatadditionally contain the FeS-B coding sequence only added the DNAsequence that encodes the peptide normally removed upon transport intothe chloroplast.

1. pSSU-SU11. This plasmid was prepared and contained the DNA encodingthe first 69 amino acids of the SSU301 gene from petunia (Dean et al.,Mol. Gen. Genet. 206:465-474 (1987) herein incorporated by reference ).(57 amino acid chloroplast transit peptide and 12 amino acids of matureSSU301) added onto the NH₂ -terminus of the P450SU1 coding sequence. TheSSU301 promoter and 5' and 3' untranslated sequences (Dean et al., Mol.Gen. Genet. 206:465-474 (1987)) of the SSU301 gene providedtranscription and translation signals for expression of this protein inplants. For propogation in E. coli pSSU-SS11 included the sequences ofthe plasmid pUC118. A diagram of pSSU-SU11 is shown in FIG. 10B.

2. pSSU-SU12. This plasmid was prepared like pSSU-SU11 except that itcontained only the DNA encoding the 57 amino acid chloroplast transitpeptide of the petunia SSU301 gene added onto the amino terminus ofP450SU1. A diagram of pSSU-SU12 is shown in FIG. 10C.

3. pCab-SU13. This plasmid was prepared containing the DNA encoding thefirst 61 amino acids of the petunia Cab22L gene (Dunsmuir, Nucleic AcidsRes. 13:2503-2518 (1985) herein incorporated by reference) (34 aminoacids of the chloroplast transit peptide and 27 amino acids of themature Cab22L protein) added onto the NH₂ -terminus of cytochromeP450SU1. The promoter and 5'-untranslated region of the petunia Cab22Lgene (Gidoni et al. Mol. Gen. Genet. 211:507-514 (1988) hereinincorporated by reference) and the 3'-untranslated region of the petuniaSSU301 gene provided transcription and translation signals forexpression in plant cells. For propogation in E. coli pCab-SU13 includedthe sequences of the plasmid pUC118. A diagram of pCab-SU13 is shown inFIG. 10F.

4. pCab-SU11. This plasmid is similar to pCab-SU13 expect that iscontains the DNA encoding first 48 amino acids of the petunia Cab22Lgene (Dunsmuir, Nucleic Acids Res. 13:2503-2518 (1985)) (34 amino acidsof the chloroplast transit peptide and 14 amino acids of the matureCab22L protein) added onto the NH₂ -terminus of cytochrome P450SU1. Thisplasmid can be prepared from pCab-SU13 by site-directed mutagenesis inwhich the 39 nucleotides encoding for the 13 additional amino acids ofthe Cab22L protein found in pCab-SU13 are removed from the plasmid usingmethods well known to those skilled in the art (Kunkel, T. A., et al.Proc. Natl. Acad. Sci. U.S.A., 82:499-492 (1985)) knowing that the DNAsequence spanning this area in pCab-SU13 is: ##STR4##

A diagram of pCab-SU11 is shown in FIG. 10D.

5. pCab-SU12. This plasmid is similar to pCab-SU13 except that itcontains the DNA encoding first 53 amino acids of the petunia Cab22Lgene (Dunsmuir, Nucleic Acids Res. 13:2503-2518 (1985)) (34 amino acidsof the chloroplast transit peptide and 19 amino acids of the matureCab22L protein) added onto the NH₂ -terminus of cytochrome -P450SU1.This plasmid can be prepared from pCab-SU13 by site-directed mutagenesisin which the 24 nucleotides encoding for the 8 additional amino acids ofthe Cab22L protein found in pCab-SU13 are removed from the plasmid usingmethods well known to those skilled in the art (Kunkel, T. A. et al.,Proc. Natl. Acad. Sci. U.S.A., 82:488-492 (1985)) knowing that the DNAsequence spanning this area in pCab-SU13 is as shown above. A diagram ofpCab-SU13 is shown in FIG. 10E.

6. The plasmid pSuFe2 contains two adjacent CaMV 35S promoters directingtranscription in opposite directions along with the 60 bp region fromthe 5'-untranslated region of SSU from petunia. The cytochrome P450SU1and FeS-B coding sequences, however, have sequences encoding the 57amino acid chloroplast transit peptide from SSU added at the start ofeach coding sequence. The FeS-B gene contains the nos 3'-untranslatedsequence while the P450SU1 gene contains the petunia SSU 3'-untranslatedsequence. This construction constitutively expresses cytochrome P450SU1and FeS-B and targets their resulting proteins to the chloroplasts orplastids of plants and upon entry into the chloroplast and processing ofthe transit peptide the mature P450SU1 or FeS-B protein will be presentwithout any additional sequences. A diagram of pSuFe2 is shown in FIG.15B.

7. The plasmid pSuFe3 contains two adjacent SSU promoters from petuniadirecting transcription in opposite directions. These two promotersexpress cytochrome P450SU1 and FeS-B coding sequences that have hadsequences encoding the 57 amino acid chloroplast transit peptide fromSSU added at the start of each coding sequence. The FeS-B gene has thenos 3'-untranslated sequence while cytochrome P450SU1 has the petuniaSSU 3'-untranslated sequence. This construction expresses bothcytochrome P450SU1 and FeS-B in a light dependent fashion. The twoproteins are also targeted to the chloroplast where, after proteolyticcleavage of the transit peptide, they exit without any additionalsequences being added. A diagram of pSuFe3 is shown in FIG. 15C.

8. The plasmid pSuFe4 is similar to pSuFe3 except that instead of thetwo SSU promoters being adjacent to one another, the nos 3'-untranslatedsequence and petunia SSU 3'-untranslated sequence are adjacent to oneanother. All of the components of the two plasmids are otherwise thesame. A diagram of pSuFe4 is shown in FIG. 15D.

Seven of the plasmids described above, i.e., two for cytoplasmicexpression and five for chloroplast expression, were deposited in theAmerican Type Culture Collection under the following access numbers.pCab-SU11 and pCab-SU12 can be made from pCab-SU13 as described above bythose skilled in the art. pSuFe4 can be made from pSuFe3 as describedbelow by those skilled in the art.

    ______________________________________                                        P450SU1       ATCC accession                                                  construction  number                                                          ______________________________________                                        pSU17         67995                                                           pSSU-SU11     67994                                                           pSSU-SU12     67993                                                           pCab-SU13     67992                                                           pSuFe1                                                                        pSuFe2                                                                        pSuFe3                                                                        ______________________________________                                    

Plasmids for expression of cytochrome P450SU1 with or without FeS-B inthe cytoplasm of plant cells.

1. Construction of pSU17. Flow diagram is shown in FIGS. 17A to 17D.

Plasmids used in sequencing the genes for cytochrome P450SU1 and FeS-Bwere derived by exonuclease III deletion (Henikoff, Gene 28:351-359,1984) from either end of the 2.4 kb BamHI DNA fragment that containsthese genes. One of these plasmids, pSU12-1.8, has an endpoint 6 bpdownstream from the translation termination codon for P450SU1 whilestill containing the entire coding sequence for cytochrome P450SU1. Thisplasmid pSU12-1.8, was used as a starting place to develop DNAconstructions that would express the P450SU1 protein in plant cells.Addition of sequences to the 3'-end of the P450SU1 coding sequence arerequired for translation in plants. pSU12-1.8 was digested with HindIIIand the site was filled in using the Klenow fragment of DNA polymerase I(Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y. (1982)). This plasmid was cutwith EcoRI and the approximately 1.3 kb EcoRI-blunt end DNA fragmentcontaining the P450SU1 coding sequence was subcloned into EcoRI-HincIIcut pUC118 creating pSU14. The 3' nontranslated sequence from the SSU301gene (encoding the small subunit of ribulose bisphosphate carboxylase[SSU] from petunia) was fused to the 3'-end of the P450SU1 codingsequence as follows. pSSU3033, a plasmid containing the SSU301 gene witha BglII site at the TGA stop codon of the translational stop for SSU (C.Dean et al. The Plant Cell 1:201-208 (1989)) was cut with BglII and theends blunted with the Klenow fragment of DNA polymerase I (Maniatis etal., Molecular Cloning: a Laboratory Manual, Cold Spring Harbor Press,Cold Spring Harbor, N.Y. (1982)) and then cut with BamHI. The resulting1.45 kb blunt end-BamHI DNA fragment containing the 3'-end of the SSU301gene was subcloned into BamHI-HincII cut pUC118 and the resultingplasmid called pSSU3040 . A three component ligation consisting of 1.the P450SU1 coding region from pSU14 (a 1.3 kb EcoRI-PstI DNA fragment),2. the 3'-untranslated region from the SSU301 gene (a 1.45 kb PstI-BamHIfragment from pSSU3040) and 3. BamHI-EcoRI cleaved pUC118 was performed(Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y. (1982)) to create pSU15. A ScaIsite was introduced at the ATG start codon: ##STR5## for P450SU1 inpSU15 by in vitro mutagenesis (Kunkel, T. A. PNAS 82: 488-492, (1985))creating pSU16. This creates a P450SU1 "cassette" which was used infurther constructions to express the P450SU1 gene in plants. A plasmid,p35S(J):Cab22L-CH, that contains the Cauliflower Mosaic Virus (CaMV) 35Spromoter and the 5' untranslated region from the petunia chlorophyll a/bbinding protein gene "Cab 22L" (Harpster et al. Molecular and GeneralGenetics, 212: 182-190, 1988) was used to provide a promoter forexpression of P450SU1 in plants. A 1.2 kb EcoRI-NcoI (blunted with theKlenow fragment of DNA polymerase I, (Maniatis et al., MolecularCloning: a Laboratory Manual, Cold Spring Harbor Press, Cold SpringHarbor, N.Y. (1982)) from p35S(J):Cab22L-CH was ligated toScaI(blunt)-EcoRI cleaved pSU16 to create pSU17. When the filled in NcoIsite from p35S(J):Cab22L-CH and the ScaI site from pSU17 were fusedtogether in this construction the ATG start codon for cytochrome P450SU1was regenerated. This construction, pSU17, when introduced into plantsexpressed cytochrome P450SU1 in the cytoplasm of the plant cell.

In FIGS. 17A to 17D the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 17A:                                                                 A        1) Hind III cut and fill in with Klenow                                       2) EcoRI cut                                                         B        EcoRI + HincII cut                                                   For FIG. 17C:                                                                 C        EcoRI + PstI cut                                                     D        BamHI + EcoRI cut                                                    E        BamHI + PstI cut                                                     F        3 component ligation                                                 For FIG. 17B:                                                                 G        1) BglII and fill in with Klenow                                              2) BamHI cut                                                         H        BamHI + HincII                                                       I        Ligate                                                               For FIG. 17D:                                                                 J        Site directed mutation of P450SU1 ATG start                                   site to ScaI site                                                    K        1) ScaI                                                                       2) EcoRI cut                                                         L        1) NcoI cut and fill in with Klenow                                           2) EcoRI cut                                                         M        Ligate                                                               ______________________________________                                    

2. Construction of plasmid pSuFe1. Flow diagram is shown in FIGS. 18A to18D.

Plasmids used in sequencing the genes for cytochrome P450SU1 and FeS-Bwere derived by exonuclease III deletion (Henikoff, Gene 28:351-359,1984) from either end of the 2.4 kb BamHI DNA fragment that containsthese genes. One of these plasmids, pSU12-2.04, has an endpoint severalbase pairs downstream of the step codon of FeS-B. By site-directedmutagenesis (Kunkel, T. A. PNAS 82: 488-492, (1985)) a ScaI site wasintroduced at the ATG initiation codon creating the plasmid pFeSB-1.02and changing the sequence at the translation initiation site from##STR6## A 0.24 kb ScaI-XbaI fragment, containing the FeS-B codingsequence from pFeSB-1.02 was cloned into p29593 that had been NcoI cutand the ends filled in with the Klenow fragment of DNA polymerase I(Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor Press, Cold Spring Harbor, N.Y. (1982)) and then subcut with XbaIcreating pFeSB-3. The filled in NcoI site from p29593 recreates the ATGinitiation codon for FeS-B. p29593 is a derivative of p35S(j):Cab22L CH(Harpster et al. Mol. Gen. Genet. 212: 182-190 (1988)) that has had aBglII site introduced by site-directed mutagenesis (Kunkel, PNAS82:488-492 (1985)) approximately 190 bp upstream of the transcriptionstart point (using the DNA sequence of R. C. Gardner et al., NucleicAcids Res. 9:2871-2888 (1981) nucleotide 7238 G changed to a C andnucleotide 7239 C changed to a T) of the CaMV 35S promoter (J. Odell etal. Nature 313:810-813 (1985)). p29593 contains the 35S promoter ofCauliflower Mosaic Virus (CaMV) and the 3' untranslated sequence of thenopaline synthase gene (nos) from T-DNA of Agrobacterium tumefaciens(Depicker et al. J. Mol. Appl. Genet. 1:561-573 (1982)). pSU17, fromabove, was digested with BamHI and partially digested with XhoI forminga 2.86 kb DNA fragment containing the cytochrome P450SU1 coding sequenceand the 3' untranslated region of the petunia SSU gene. This was ligatedwith XhoI and BamHI digested p29593 to form pSU20. The 3'-untranslatedregion of the SSU gene was removed from pSU20 by partial PstI digestionand blunting the ends with T4 DNA polymerase (Maniatis et al., MolecularCloning: a Laboratory Manual, Cold Spring Harbor Press, Cold SpringHarbor, N.Y. (1982)) and then digesting with BamHI and filling the endswith the Klenow fragment of DNA polymerase I (Maniatis et al., MolecularCloning: a Laboratory Manual, Cold Spring Harbor Press, Cold SpringHarbor, N.Y. (1982)). The resulting DNA was intramolecularly ligatedforming pSU21. A 2.6 kb partially BglII digested and HindIII digestedDNA fragment of pSU21 was isolated that contained the CaMV 35S promoter,P450SU1 coding sequence and the nos 3' untranslated sequence. This DNAfragment was ligated to a 0.76 kb HindIII-BglII DNA fragment of pFeSB-3containing the CaMV 35S promoter, FeS-B coding sequence and nos gene 3'untranslated sequence forming pSUFe1. pSUFe1 contains 2 CaMV 35Spromoters one that transcribes the FeS-B coding sequence and nos gene 3'untranslated sequence and the other that transcribes the P450SU1 codingsequence and a nos gene 3' untranslated sequence. The plasmid pSUFe1when transformed into plant cells drives expression of p450SU1 and FeS-Bin the cytoplasm.

In FIGS. 18A to 18D the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 18A:                                                                 A        1) XhoI partial cut                                                           2) BamHI cut                                                         B        XhoI + BamHI cut                                                     C        Ligate                                                               For FIG. 18B:                                                                 D        1) PstI partial, T4 blunt ends                                                2) BamHI cut and fill in with Klenow                                 E        Recircularize                                                        For FIG. 18C:                                                                 F        1) NcoI and fill in with Klenow                                               2) XbaI cut                                                          G        Site directed mutagenesis of FeS-B ATG start                                  to ScaI site                                                         H        ScaI + XbaI cut                                                      I        Ligate                                                               For FIG. 18D:                                                                 J        BglII + HindIII cut                                                  K        1) BglII partial                                                              2) HindIII cut                                                       L        Ligate with HindIII cut pUC118                                       ______________________________________                                    

Plasmids that direct the expression of cytochrome P450SU1 with orwithout FeS-B to the chloroplasts of plant cells

In order to express the cytochrome P450SU1 protein or FeS-B in thechloroplasts of plants, plasmids were constructed using 5' promoterregions, coding regions of the transit peptide sequences, and in somecases the mature coding sequence of genes encoding proteins normallyimported into the chloroplasts of plants. The naturally chloroplastimported genes used in these plasmids were those for ribulosebisphosphate carboxylase (SSU) and the chlorophyll a/b binding protein(Cab) both from petunia. Plasmids were made that added DNA encoding foramino terminal amino acid sequence that is normally removed upontransport into chloroplasts. Other plasmids were made that added DNAencoding the chloroplast transit peptide sequence and up to 27 aminoacids of the mature transported protein onto the DNA encoding cytochromeP450SU1.

1. Construction of plasmids pSSU-SU11 and pSSU-SU12. Flow diagram isshown in FIGS. 19A and 19B.

A. 1.8 kb ClaI(end blunted with Klenow fragment of DNA polymeraseI)-BamHI DNA fragment from pSSU3019(Dean et al. The Plant Cell1:201-208, (1989)) a clone that contains the 5' and 3' flanking regionsbut lacks the introns of the SSU301 gene was cloned into SmaI-BamHIcleaved pUC8 generating pSSU3043. The polylinker of pUC8 adds onto theSSU301 gene an EcoRI site to be used in the constructions. To make thefusion between the chloroplast transit peptide and P450SU1 and EcoRVsite was introduced by site directed mutagenesis (Kunkel, PNAS 82:488-492, (1985)) into the mature SSU301 coding sequence after amino acid12 creating pSSU3044. A 1.4 kb EcoRI-EcoRV DNA fragment from pSSU3044containing the SSU301 promoter and the DNA encoding the amino-terminusof the SSU301 protein was cloned into EcoRI-ScaI cleaved pSU16 creatingpSSU-SU11. pSSU-SU11 encodes 12 extra amino acids in addition to thechloroplast transit peptide from the SSU301 protein added onto the DNAencoding the amino terminus of the P450SU1 protein. To create a precisefusion of the chloroplast transmit peptide coding sequence with theP450SU1 coding sequence, an oligonucleotide directed site specificdeletion (Kunkel, PNAS 82: 488-492, (1985)) was used to loop out theextra nucleotides between the transit peptide and the amino terminus ofP450SU1. The resulting plasmid, pSSU-SU12, contains a perfect fusionbetween the transit peptide of the SSU301 gene and the amino terminus ofP450SU1. The plasmids pSSU-SU11 and pSSU-SU12 express cytochrome P450SU1in plant cells that is targeted to the chloroplasts.

In FIGS. 19A and 19B the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 19A:                                                                 A        1) ClaI cut and fill in with Klenow                                           2) BamHI cut                                                         B        SmaI + BamHI                                                         C        Ligate                                                               D        Site directed mutagenesis creating EcoRV                                      site at aa12 of mature SSU301 protein                                For FIG. 19B:                                                                 E        EcoRI + EcoRV cut                                                    F        ScaI + EcoRI                                                         G        Ligate                                                               H        Oligonucleotide loopout of sequences coding                                   for 12aa of SSU mature peptide.                                      ______________________________________                                    

2. Construction of plasmids pCab-SU11, pCab-SU12 and pCab-SU13. Flowdiagram is shown in FIGS. 20A to 20C.

To make the chlorophyll a/b binding protein fusion to P450SU1, a 950 bpBalI-SacI DNA fragment of the petunia Cab22L gene (Dunsmuir, NucleicAcids Res. 13:2503-2518 (1985)) containing the Cab22L promoter,chloroplast transit peptide coding sequence and part of the matureCab22L coding sequence was cloned into SmaI-SacI digested pBluescriptKS+(Stratagene Inc. San Diego, Calif. 92121) creating pCab22LT. A ScaIsite was created by site-directed mutagenesis after the codon for aminoacid 14 of the mature Cab protein coding sequence of pCab22LT creatingpCab22LT1. The Cab22L promoter, codons encoding the transit peptide and14 amino acids of the mature Cab22L protein were subcloned as a 1.2 kbEcoRI-ScaI fragment of pCab22LT1 into EcoRI-ScaI cleaved pSU16 creatingpCab-SU11. An oligonucleotide was made that looped in 39 nucleotides(Kunkel, PNAS 82: 488-492, (1985)) encoding amino acids 15-27 of themature Cab22L protein into the junction between the Cab22L codingsequence and the P450SU1 coding sequence creating pCab-SU13. pCab-SU13encodes a protein that contains the Cab22L chloroplast transit sequence,27 amino acids of the mature Cab22L protein fused to the amino terminusof the P450SU1 protein. A SmaI site was created by site-directedmutagenesis (Kunkel, PNAS 82:488-492, (1985)) at amino acid 19 ofpCab22LT creating pCab22LT2. The Cab22L promoter, codons encoding thetransit peptide and 19 amino acids of the mature Cab22L protein weresubcloned as a 1.2 kb EcoRI-SmaI DNA fragment of pCab22LT2 intoEcoRI-ScaI cleaved pSU16 creating pCab-SU12. The plasmids pCab-SU11,pCab-SU12 and pCab-SU13 express cytochrome P450SU1 in plant cells thatis targeted to the chloroplasts.

In FIGS. 20A to 20C the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 20A:                                                                 A        SmaI + SacI cut                                                      B        Ligate                                                               C        Site directed mutagenesis of Cab-M at amino                                   acid 14 to ScaI site                                                 D        Site directed mutagenesis of Cab-M at amino                                   acid 19 to ScaI site                                                 For FIG. 20B:                                                                 E        SmaI + EcoRI cut                                                     F        EcoRI + ScaI cut                                                     G        Ligate                                                               For FIG. 20C:                                                                 F        EcoRI + ScaI cut                                                     H        ScaI + EcoRI cut                                                     I        Ligate                                                               J        Use oligonucleotide to loop in 39                                             nucelotides coding for amino acid 15-27 of                                    Cab mature at ScaI site                                              ______________________________________                                    

3. Construction of plasmids pSUFe3 and pSUFe4. Flow diagram is shown inFIGS. 21A to 21D.

p29593 (see construction of pSUFe1) was cleaved with NcoI and XbaI andligated with a 1 kb NcoI-XbaI DNA fragment from pFeSB-1.02 (seeconstruction of pSUFe1) that contains the FeS-B coding sequence. Thisforms plasmid pFenos1 and puts the 3' untranslated sequence of the nosgene from p29593 downstream of the FeS-B coding sequence. pFenos1 wascleaved with BglII removing a 0.75 kb BglII DNA fragment and theremaining BglII DNA fragment was recircularized creating pFenos2. A 1.4kb EcoRI-EcoRV DNA fragment from pSSU3044 (see construction ofpSSU-SU11) that contains the promoter, sequences coding for thechloroplast transit sequence and the first 12 mature amino acids of themature protein of the petunia SSU301 gene was isolated. This fragmentwas ligated with pSFenos2 that had been partially digested with ScaI andcompletely digested with EcoRI creating pSFenos1. pSFenos1 contains thepetunia SSU301 gene promoter with sequences encoding the chloroplasttransit peptide and the first 12 amino acids of the mature SSU301protein added onto the beginning of the FeS-B coding sequence. The nos3'untranslated sequences are located after the termination codon ofFeS-B. The DNA sequence that encodes the twelve amino acids of themature SSU301 protein in pSFenos1 were removed by site directedmutagenesis (Kunkel) creating pFenos2. pFenos2 was partially digestedwith HindIII and ligated to HindIII cut pGEM7Zf(+)(Promega Corporation,Madison, Wis. 53711) to put a BamHI site downstream of the nos gene 3'untranslated sequences. This plasmid is named pSFenos3. pSFenos3 was cutwith EcoRI and BamHI to give an ˜1.9 kb BamHI-EcoRI DNA fragmentcontaining the petunia SSU301 gene promoted FeS-B gene. A 4.25 kbEcoRI-BamHI DNA fragment was isolated from pSSU-SU12 (see constructionof pSSU-SU12 above) that contains the petunia SSU301 promoter, DNAencoding the chloroplast transit peptide and the 3' untranslated regionflanking the cytochrome P450SU1 coding sequence. These two BamHI-EcoRIDNA fragments were ligated together along with EcoRI digested pUC118 tocreate pSUFe3. The same two BamHI-EcoRI DNA fragments were ligatedtogether along with BamHI digest pUC118 to create pSUFe4.

Both pSUFe3 and pSUFe4 contain 1). the petunia SSU301 promoter such thatin plants it will transcribe sequences encoding the SSU301 chloroplasttransit peptide linked to the coding sequence for FeS-B and the nos gene3' untranslated sequence and 2). a second petunia SSU301 promoter suchthat in plants it will transcribe sulfonylureas encoding the SSU301chloroplast transit peptide linked to the coding sequence for cytochromeP450SU1 and SSU301 gene 3' untranslated sequence. pSUFe3 has these twosegments oriented such that the two SSU301 promoters are adjacent to oneanother. pSUFe4 has these two segments oriented such that the nos gene3' untranslated sequence and the SSU301 3' untranslated sequence areadjacent to one another.

In FIGS. 21A to 21D the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 21A:                                                                 A.       NcoI + XbaI digestion of pFeSB-1.02                                  B.       NcoI + XbaI digestion of p29593                                      C.       1) BglII digestion and                                                        2) Recircularization of pFenos1                                      For FIG. 21B:                                                                 D.       ScaI partial digestion and EcoRI digestion                                    of pFenos2                                                           E.       EcoRI + EcoRV digestion of pSSU3044                                  F.       Site specific oligonucleotide directed                                        deletion of nucleotides encoding SSU mature                                   sequence                                                             For FIG. 21C:                                                                 G.       Partial HindIII digestion of pSFenos2                                H.       HindIII digestion of pGEM7ZF(+)                                      For FIG. 21D:                                                                 I.       EcoRI + BamHI digestion of pSFenos3                                  J.       EcoRI + BamHI digestion of pSSU-SU12                                 K.       EcoRI digestion of pUC118                                            L.       BamHI digestion of pUC118                                            M.       3 component ligation                                                 N.       3 component ligation                                                 ______________________________________                                    

4. Construction of pSUFe2. Flow diagram shown in FIGS. 22A and 22B.

p29593 can be cut with BamHI and ligated to an EcoRI-BamHI adaptor (NewEngland Biolabs, Inc., Beverly, Mass.) with subsequent recircularizationforming p29593-1. This puts an EcoRI site in p29593-1 at the position ofthe BamHI site in p29593. An ˜2.2 kb EcoRI-BglII DNA fragment ofp29593-1 containing the CaMV 35 S promoter and petunia Cab 22L 5'untranslated sequence can be ligated to p29593 cut with EcoRI andpartially digested with BglII forming p29593-2. p29593-2 contains twoadjacent CaMV 35S promoters and petunia Cab 22L 5' untranslatedsequences arranged such that transcription from the two promoters wouldbe in opposite directions. A 1.3 kb NcoI fragment from p29593-2containing the two CaMV 35S promoters and Cab22L 5' untranslatedsequences can then be ligated to pSUFe3 that has its two petunia SSU301promoters removed by partial NcoI digestion to form pSUFe2. pSUFe2 issimilar to pSUFe1 except that both the cytochrome P450SU1 and FeS-Bcoding sequences have sequences for the petunia SSU301 gene chloroplasttransit peptide fused to them.

In FIGS. 22A and 22B the following steps are designated with letters atthe arrows:

    ______________________________________                                        For FIG. 22A:                                                                 A.       1) BamHI digestion and addition of                                            BamHI-EcoRI adapters to p29593 and                                            2) Recircularization                                                 B.       BglII partial digestion and EcoRI digestion                                   of p29593                                                            C.       BglII + EcoRI digestion of p29593-1                                  For FIG. 22B:                                                                 D.       NcoI digestion of p29593-2                                           E.       NcoI partial digestion of pSUFe3                                     ______________________________________                                    

C. Introduction of construct into T-DNA plasmids

Six of the constructs (i.e., pSU17, pSSU-SU11, pSSU-SU12, pCabSU11,pCabSU12 and pCabSU13) containing the P450SU1 coding sequence withpromoters from plant genes were digested with BamHI and inserted intothe plasmid pAGS135 at its unique BamHI site. Plasmid pAGS135 wasderived from pAGS112 (P. van den Elzen et al. Plant Mol. Biol.5:149-154, 1985, herein incorporated by reference,) by removal of theXhoI site outside of the T-DNA right border following digestion ofpAGS112 DNA with XhoI, treatment with the Klenow fragment of DNApolymerase I to blunt the ends and then self ligating. The plasmidpAGS112 was derived from the wide host-range vector pLAFR (Friedman etal. Gene 18:289-296, herein incorporated by reference) by insertion ofan EcoRI fragment in which the T-DNA borders flank a gene for expressingkanamycin resistance in plants and multiple cloning sites. pAGS501,pAGS502 and pZS96 are similar to pAGS135 in that they are T-DNA bordercontaining plasmids expressing kanamycin resistance in plants.

A summary of how pAGS501, pAGS502 and pZS96 were made is describedbelow.

pAGS501 and 502 were constructed as follows. pRK290 (G. Ditta et al.,Proc. Natl. Acad. Sci. U.S.A., 77:7347-7351, (1980)) was cut with EcoRIand the ends filled in with the Klenow fragment by DNA polymerase I (T.Maniatis et al., Molecular Cloning: a Laboratory Manual, Cold SpringHarbor, N.Y. (1982)). pAGS111 (P. J. van den Elzen et al., Plant Mol.Biol. 5:149-154, (1985)) was cut with EcoRI and HindIII and the endsfilled in with the Klenow fragment of DNA polymerase I (T. Maniatis etal., (1982)). The 6.7 kb DNA fragment from pAGS111 containing the leftand right borders of T-DNA and the kanamycin nucelotidylphosphotransferase gene under the control of the nopaline synthetasepromoter was ligated to the cleaved pRK290 DNA creating p1881. p1881 wascut with XhoI, the ends blunted with the Klenow fragment of DNApolymerase I and circularly ligated creating p1882. p1882 was cut withBamHI and ligated to a double stranded oligonucleotide containing XbaI,HindIII, XhoI, EcoRI and HpaI sites. The ends of the double strandedoligonucleotide are such that when ligated to BamHI cut p1882 one endrecreates a BamHI site while the other end does not. Plasmids pAGS501and pAGS502 are the two possible results of such a ligation. Bothplasmids contain BamHI, HindIII and EcoRI sites between the T-DNAborders that can be used as cloning sites for DNA to be mobilized intoplants.

In FIGS. 23A and 23B, the following steps are designated with letters atthe arrows:

    ______________________________________                                        A.      1) HindIII + EcoRI digestion of pAGS111                                       2) fill in of restriction endocunlease ends                                   with the Klenow fragment of DNA                                               polymeraseI                                                           B.      1) EcoRI digestion of pRK290                                                  2) fill in of restriction endocunlease ends                                   of pRK290                                                                     3) ligation of pRK290 with the ˜6.7 kb T-DNA                            fragment of pAGS111                                                   C.      1) XhoI digestion of p1881                                                    2) fill in of restriction endocunlease ends                                   of p1881                                                                      3) intramolecular ligation of p1881                                   D.      1) BamHI digestion of p1882                                                   2) ligation of HpaI, EcoRI, HindIII, XbaI,                                    BamHI oligonucleotide with p1882.                                     ______________________________________                                    

pZS96 was constructed as follows. This plasmid utilizes the replicationand stability functions of pVS1 for use in Agrobacterium (Itoh et al.,Plasmid, 11:206-220 (1984)). A derivative of pVS1, pGV910 (J. Lemans etal., Gene, 19:361-364 (1982)) was cut with BamHI and SalI and the 8.0 kbHamHI-SalI DNA fragment containing the replication origin and stabilityfunctions was ligated to a 4.1 kb BaHI-SalI fragment from pBR322(Bolivar et al., Gene, 2:95-113 (1977)) creating pZS67. pZS67 was cutwith SacI and PvuII and the ends blunted with T4 polymerase (T. Maniatiset al., 1982) creating the 8.6 kb plasmid pZS68. pZS68 was cut withBamHI and the ends filled in with the Klenow fragment of DNA polymeraseI (T. Maniatis et al., 1982) and recircularized creating pZS69. Theunique PstI site in pZS69 was removed by exchanging the 222 bpAvaII-AvaII fragment within the ampicillin resistance gene containingthe PstI site with a similar fragment from pUC19 (C. Yanisch-Peron etal. Gene 33:103-119, (1985)) that does not contain a PstI site creatingpZS71. The T-DNA region of pAGS111 (P. J. can den Elzen et al., (1985))was cut out as a 5.7 kb EcoRI-HindIII fragment and cloned intoEcoRI-HindIII cleaved pZS71 creating pZS73 (12.3 kb). pZS73 was cut withEcoRI, the ends filled in with the Klenow fragment of DNA polymerase I(T. Maniatis et al., 1982) and the plasmid recircularized to form pZS74.pZS74 was cut with HindIII, the ends filled in with the Klenow fragmentof DNA polymerase I (T. Maniatis et al. 1982) and the plasmidrecircularized to form pZS75. A 444 bp HaeII-HaeII DNA fragment frompUC19 containing the polylinker region whose ends had been blunted withT4 DNA polymerase (T. Maniatis et al., 1982) was cloned into pZS75 thathad been cut with BamHI sites that are not within the polylinker region.This was accomplished through sequential steps of separate partialdigestions with KpnI, SalI or BamHI, filling the ends with either theKlenow fragment of DNA polymerase I or T4 DNA polymerase (T. Maniatis etal, 1982) and recircularizing the plasmimd.

In FIG. 24A the following steps are designated with letters at thearrows:

    ______________________________________                                        A.       1) BamHI + SalI digestion of pGV910 and                                       pBR322                                                                        2) ligation of 4.1 kb BamHI-SalI pBR322                                       fragment with the 8.0 kb BamHI-SalI                                           pGV910 fragment                                                      B.       1) PvuII + SacII digestion of pZS67                                           2) blunt restriction endonuclease ends with                                   T4 DNA polymerase                                                             3) intramolecular ligation.                                          ______________________________________                                    

In FIG. 24B the following steps are designated with letters at thearrows.

    ______________________________________                                        C.       1) BamHI digestion of pZS68                                                   2) fill in of restriction endonuclease ends                                   with the Klenow fragment of DNA                                               polymerase I                                                                  3) intramolecular ligation                                           D.       AvaII digestion of pUC19                                             E.       1) AvaII digestion of pZS69                                                   2) ligation of the 222 bp AvaII fragment of                                   pUC19 with the 11.9 kb AvaII fragment of                                      pZS69.                                                               ______________________________________                                    

In FIG. 24C the following steps are designated with letters at thearrows.

    ______________________________________                                        F.       HindIII + EcoRI digestion of pAGS111                                 G.       1) EcoRI + HindIII digestion of pZS71                                         2) Ligation of the ˜5.7 kb HindIII-EcoRI                                fragment of pAGS111 with HindIII-EcoRI                                        cut pZS71                                                            H.       1) HindIII digestion of pZS73 and fill in                                     restriction ends                                                              2) intramolecular ligation                                                    3) EcoRI digestion of plasmid from 2)                                         4) intramolecular ligation.                                          ______________________________________                                    

In FIG. 24D the following steps are designated with letters at thearrows.

    ______________________________________                                        I.       1) HaeII digestion of pUC19 and blunt ends                                    with T4 DNA polymerase                                                        2) BamHI digestion of pZS75 and fill in                                       restriction ends                                                              3) ligate digested pZS75 with ˜440 bp HaeII                             fragment of pUC19                                                    J.       1) KpnI digestion, blunt ends with T4 DNA                                     polymerase                                                                    2) intramolecular ligation                                                    3) SalI partial digestion of plasmid from                                     2), blunt ends with Klenow fragment of                                        DNA polymerase I                                                              4) intramolecular ligation                                                    5) BamHI partial digestion of plasmid from                                    4), blunt ends with Klenow fragment of                                        DNA polymerase I                                                              6) intramolecular ligation.                                          ______________________________________                                    

These plasmids were used as folllows to clone the segments of pSUFe1,pSUFe2, pSUFe3 and pSUFe4 that enable expression of cytochrome P450SU1and FeS-B in plants. The ˜3.4 kb HindIII fragment of pSUFe1 containingthe two CaMV 35S promoters and nos 3' untranslated sequences along withthe cytochrome P450SU1 and FeS-B coding sequences was cloned intoHindIII cut pAGS502 creating pSUFe11. The ˜4.75 kb BamHI fragment ofpSUFe2 containing two CaMV 35S promoters, nos 3' untranslated sequence,SSU301 3' untranslated sequence and the coding sequences of P450SU1 andFeS-B each linked to sequences encoding the chloroplast transit peptideof the SSU301 gene was cloned into BamHI cut pAGS501 creating pSUFe21.The 6.3 kb BamHI fragment of pSUFe3 containing two petunia SSU301promoters, nos 3' untranslated sequence, SSU301 3' untranslated sequenceand the coding sequence of P450SU1 and FeS-B each linked to sequencesencoding the chloroplast transit peptide of the SSU301 gene was clonedinto BamHI cut pZS96 DNA creating pSUFe31. The 6.3 kb EcoRI fragment ofpSUFe4 containing two petunia SSU301 promoters, nos 3' untranslatedsequence, SSU301 3' untranslated sequence and the coding sequences ofP450SU1 and FeS-B each linked to sequences encoding the chloroplasttransit peptide of the SSU301 gene was cloned into EcoRI cut pZS96 DNAcreating pSUFe41. Below is a list indicating the expression constructsdescribed above and the name for the plasmid made from each when clonedinto pAGS135, pAGS501, pAGS502 or pZS96.

    ______________________________________                                        P450SU1                                                                       construction        Plasmids                                                  ______________________________________                                        pSU17               pSU18                                                     pSSU-SU11           pSSU-SU111                                                pSSU-SU12           pSSU-SU121                                                pCab-SU11           pCab-SU111                                                pCab-SU12           pCab-SU121                                                pCab-SU13           pCab-SU131                                                pSuFe1              pSuFe11                                                   pSuFe2              pSuFe21                                                   pSuFe3              pSuFe31                                                   pSuFe4              pSuFe41                                                   ______________________________________                                    

D. Transfer to Agrobacterium and into tobacco

The plasmids listed above were mobilized into the Agrobacterium strainLBA4404/pAL4404 (Hoekema et al. Nature 303:179-180, 1983, hereinincorporated by reference) using tri-parental matings (Ruvkin andAusubel, Nature 289:85-88, 1981, herein incorporated by reference). Theresulting Agrobacterium strains were then cocultivated with protoplasts(van den Elzen et al. Plant Mol. Biol. 5:149-154) or leaf disks (Horschet al. Science 227:1229-1231, 1985) of Nicotiana tabacum cv. Wisconsin38 and kanamycin resistant transformants were selected.

Kanamycin resistant transformed tobacco plants were regenerated from thetransformed protoplasts or leaf disks and the leaves of plants weretested for mRNA expression of the P450SU1 and FeS-B coding sequences byprimer extension. Those plants that showed moderate to high levels ofmRNA were allowed to flower, were self-pollinated and seed obtained fromeach. Several different independent transformed plants originating fromeach P450SU1 expression construction were isolated. The following Table16 lists the parent construct, promoter used and additions to theP450SU1 coding sequence for each plant line used.

                  TABLE 16                                                        ______________________________________                                                                           Amino                                                  Parent                 Terminal                                   Plant Line  plasmid     Promoter   Additions                                  ______________________________________                                        A. Plants Expressing Cytochrome P450SU1                                       W38         none        none                                                  AGS112      pAGS112     none (no                                                                      P450 gene)                                            SU18.8      pSU18       CaMV       none                                       SU18.14     "           "          "                                          SU18.15     "           "          "                                          SSU-SU111.5 pSSU-SU111  SSU        SSU                                                                           transit                                                                       sequence +                                                                    12 extra                                                                      amino acids                                                                   of mature                                                                     SSU                                        SSU-SU121.3 pSSU-SU121  SSU        SSU                                                                           Transit                                                                       Sequence                                   Cab-SU111.8 pCab-SU111  Cab        Cab                                                                           transit                                                                       sequence +                                                                    14 amino                                                                      acids of                                                                      mature Cab                                 Cab-SU121.5 pCab-SU121  Cab        Cab                                                                           transit                                                                       sequence +                                                                    19 amino                                                                      acids of                                                                      mature Cab                                 Cab-SU131.5 pCab-SU131  Cab        Cab                                                                           transit                                                                       sequence +                                                                    27 amino                                                                      acids of                                                                      mature Cab                                 B. Plants Expressing Cytochrome P450SU1 and FeS-B                             SuFe11.1    pSuFe11     CaMv       None                                       SuFe11.3    pSuFe11     35S        None                                       SuFe11.4    pSuFe11     35S        None                                       SuFe11.7    pSuFe11     35S        None                                       SuFe11.8    pSuFe11     35S        None                                       SuFe11.1    pSuFe11     35S        None                                       SuFe21.2    pSuFe21     35S        SSU                                                                           Transit                                                                       Sequence                                   SuFe21.5    pSuFe21     35S        SSU                                                                           Transit                                                                       Sequence                                   SuFe21.6    pSuFe21     35S        SSU                                                                           Transit                                                                       Sequence                                   SuFe21.7    pSuFe21     35S        SSU                                                                           Transit                                                                       Sequence                                   SuFe21.8    pSuFe21     35S        SSU                                                                           Transit                                                                       Sequence                                   SuFe31.13   pSuFe31     SSU        SSU                                                                           Transit                                                                       Sequence                                   SuFe31.28   pSuFe31     SSU        SSU                                                                           Transit                                                                       Sequence                                   SuFe41.34   pSuFe41     SSU        SSU                                                                           Transit                                                                       Sequence                                   SuFe41.37   pSuFe41     SSU        SSU                                                                           Transit                                                                       Sequence                                   SuFe41.56   pSuFe41     SSU        SSU                                                                           Transit                                                                       Sequence                                   SuFe41.60   pSuFe41     SSU        SSU                                                                           Transit                                                                       Sequence                                   ______________________________________                                    

EXAMPLE 20 P450 enzyme activity in tissues of transformed tobacco A.Experimental methods

Plants were grown from tobacco seed produced by self-pollinatedtransformed plants in Metro-Mix® 350 under 16 hour light (lightintensity of 400 μEinsteins per second per square meter at pot level,22° C. and 80% relative humidity) followed by 8 hours of dark (18° C.and 70 to 80% relative humidity) and watered three times daily with halfstrength Hoagland's solution. The presence of the cytochrome P450protein in individual plants was confirmed by Western blot analysisbefore testing for sulfonylurea metabolism.

During growth, the tobacco plants produced leaves attached to the mainstalk, none of which were of the same age or size. Removal of leavesattached to the main stalk of each plant forced the growth of lateralshoots which in turn produced the many leaves of similar size and ageneeded for the experiments. The leaves were excised under water with ascalpel. These leaves were transferred to cups with the uptake solution(20 ppm sulfonylurea in 1 mM potassium phosphate buffer, pH 7.0) andallowed to take up the solution through the cut leaf base for 2 hours inthe light (200 μEinsteins per second per sq. meter) at 22° C. and 86%relative humidity. At the end of the uptake period, sample leaves wereeither frozen in liquid nitrogen and stored at -20° C. (designated `0hour post-uptake samples`) or transferred to cups with phosphate bufferalone for an additional 5 hours of incubation in the light beforefreezing (designated `5 hour post-uptake samples`). In the 10001experiments some leaves were incubated for 21 hours post-uptake undercontinuous light (200 μEinsteins per second per square meter, 22° C.,and 63% relative humidity).

Individual leaves were extracted with 30 ml acetone/water (80%/20% byvolume) for 1 minutes in a Sorvall® Omni-Mixer. The brei was centrifugedto remove the tissue debris. Acetone in the supernatant was removedunder a stream of nitrogen. The resulting aqueous extract was acidifiedto pH 2 to 3 with sulfuric acid and then extracted three times withmethylene chloride. The combined methylene chloride extracts werereduced to dryness by rotary evaporation at 30° to 40° C. The dryresidue was dissolved in acetone for transfer to a vial. Oncetransferred the acetone was removed by evaporation under a stream ofnitrogen. Before HPLC analysis the dry sample was redissolved in 1.0 mlof acetonitrile/water (25%/75%). HPLC separations were carried out on aZorbax® ODS column (4.6 mm×250 mm) at 45° C. with a flow rate of 1.4 mlper minute. Separation of extract components was achieved with a 5 to80% acetonitrile gradient (with 0.1% formic acid; the balance was water)and a run time of 25 minutes. 10015 and its metabolites were detected at254 nm while ¹⁴ C-10001 and its metabolites were detected with aRadiomatic Flo-One® detector. A diode array detector was used inseparate experiments to obtain the absorbance spectra of the 10015metabolite and an 10014 standard in the HPLC analysis of severalextracts (HPLC method is described in Romesser et al., Biochem. Biophys,Res. Comm., 140:650-659 (1986)). Comparison of the metabolite absorbancespectrum with that of the 10014 confirmed the metabolite's identity.

B. Metabolism of 10015

Leaf tissues only from progeny of the transformed tobacco plants(SSU-SU111.5, SSU-SU121.3 and CAB-SU131.5) which received plasmidsengineered to direct the S. griseolus cytochrome P450 (SU1) to thechloroplast N-dealkylated 10015 to 10014 (FIG. 11). The results areshown in Table 17.

                  TABLE 17                                                        ______________________________________                                        Metabolism of 10015 to 10014 in Tobacco Leaves                                Plant Family                                                                             10014 levels                                                                              (μg/leaf)                                                                             No. of                                      construction                                                                             at 0 hour*  at 5 hour* Leaves                                      ______________________________________                                        W38        0           0          6 (3 from                                                                     each of                                                                       2 plants)                                   AGS112**   0           0          4 (4 from                                                                     one plant)                                  SSU-SU111.5#                                                                             2.1         1.8        6 (2 from                                              (+/- 1.4)   (+/- 1.4)  each of 3                                                                     plants)                                     SSU-SU121.3#                                                                             1.2         1.7        4 (2 from                                              (+/- 0.5)   (+/- 1.1)  each of 2                                                                     plants)                                     Cab-SU131.5#                                                                             1.3         2.9        8 (4 from                                              (+/- 1.0)   (+/- 1.3)  each of 2                                                                     plants)                                     SU18.8@    0           0          8 (4 from                                                                     each of 2                                                                     plants)                                     SU18.15@   0           0          2 (2 from                                                                     one plant)                                  ______________________________________                                         *Post-uptake incubation time                                                  **Control (there is no P450SU1 sequence in this plasmid)                      # The P450 sequence is chloroplast directed.                                  @ The P450 sequence is cytoplasm directed.                               

The metabolite (10014) was identified by its comigration with an 10014standard on HPLC analysis (detection at 254 nm) and by comparison of theabsorbance spectrum of the metabolite with that of the 10014 standard.The absorbance spectra were identical (FIGS. 12A and 12B). The levels of10014 in the leaves (Table 17) represent metabolic conversion of 10 to20% of the 10015 loaded into the leaves during the 2 hour uptake period(based on calculations from the volume of 10015 solution taken up). The0 and 5 hour post-uptake incubations were included to look at thekinetics of metabolism. Because of the variability in 10014 production areaction rate constant was not calculated.

Leaf tissues from the progenitor plant type, Wisconsin 38 tobacco, andprogeny of tobacco transformed with the pAGS112 plasmid (a plasmidwithout the bacterial cytochrome P450SU1 gene) were unable to produceany detectable 10014 from 10015 (Table 17). This showed that thetransgenic tobacco's ability to metabolize 10015 to 10014 was due to theexpression of the bacterial gene in the plants and not to any nativeability of the tobacco.

Leaf tissues from progeny of plants transformed with the plasmid pSU18(i.e., plant lines SU18.14 and SU18.15), also, were tested for theirability to metabolize 10015 to 10014. Under the conditions of theexperiment no conversion of 10015 to 10014 was detected (Table 17).

Transit sequences from the small subunit of carboxylase (the SUtransformants) or from the chlorophyll a/b protein (the Cabtransformants) were included in the engineered plasmids to direct thecytochrome P450SU1 protein to the chloroplast after synthesis in thecytoplasm. The mature cytochrome P450SU1 protein for the SSU-SU111.5transformant included a 14 amino acid fragment of the small subunit ofRuBP carboxylase. The SSU-SU121.3 transformant's mature cytochrome hadno additional amino acid additions. The mature cytochrome protein forthe Cab-SU131.5 transformant had an additional 27 amino acids form thechlorophyll a/b protein. Inspection of the levels of 10014 produced inthe transformants (Table 17) showed that the 14 or 27 amino acids addedto the cytochrome P450SU1 did not prevent the metabolism of 10015 to10014 in the transgenic tobacco leaf tissues.

C. Metabolism of 10001

Leaf tissues from a plant transformed with pAGS112, a plasmid notcontaining DNA encoding cytochrome P450SU1, metabolized 10001 to 10002and 10003 through O-demethylation and de-esterification, respectively(FIG. 13A). The metabolism of 10001 was assumed to be a native metabolicability of tobacco. However, it complicated the assessment of themetabolic activity of 10001 of the tissues from plants transformed withcytochrome P450SU1 containing plasmids (pSU18, pSSU-SU111. pSSU-SU121,and pCab-SU131). Although a limited number of samples were tested (eachtime point represents the average of two leaves tested), the results(FIGS. 13A, 13B and 13C) showed that after 21 hours, 10001 wasmetabolized to a significantly greater extent and more 10002 wasproduced in the leaf tissues from those plants transformed with plasmidspSSU-SU111 and pCab-SU131 than in leaf tissues from plants transformedwith pAGS112. The results indicated that the cytochrome P450SU1 wasactively metabolizing 10001 in the transgenic tobacco.

Leaf tissues from progeny of the transformants, SU18.8 and SU18.14, weretested for the ability to metabolize 10001 to 10002 and 10003. Becauseof the native ability of the tobacco to metabolize 10001, it wasdifficult to determine whether there was a contribution of the bacterialenzyme to metabolism.

EXAMPLE 21 Metabolism of 10015 by tobacco plants transformed withP450SU1

Sulfonylurea compound 10015 exhibits low phytotoxicity to a wide varietyof plant species. This compound is an excellent substrate for P450SU1,which rapidly converts it to the highly phytotoxic compound 10014 (FIG.11). Thus, tobacco plants transformed to contain P450SU1 and sprayedwith normally subtoxic rates of 10015 would be severely damaged if theycontained functional P450SU1 in sufficient quantity to allow theaccumulation of toxic compound 10014 within plant tissues.

Tobacco plants (Nicotiana tabacum cv. Wisconsin 38) transformed withplasmids pAGS112, pSU18, pSSU-SU111, pCab-SU121 or pCab-SU131 (singly)and accumulating the P450SU1 protein were identified by Western blotanalysis. Seed arising from the self pollination of individual primarytransformants designated AGS112, SU18.8, SU18.14, SSU-SU111.5,Cab-SU111.8, and Cab-SU131.5 gave rise to the plants described in thisExample. The progeny of primary AGS112 and Cab-SU121.5 transformantssegregated for single copy kanamycin resistance. In contrast, theprogeny of the plants transformed with plasmids containing P450SU1(other than Cab-SU121.5) segregated for multicopy kanamycin resistance.Thus, most plants containing the gene encoding P450SU1 and sprayed with10015 in this Example likely contained at least one, and in many casesmultiple, copies of P450SU1, while very few individuals likely carriedno copies of the gene encoding P450SU1.

Seed from transformed and nontransformed tobacco plants was germinatedin a commercial potting mix Metro-Mix® 350 for 25 days. Individualplants were then transferred to 4 inch×4 inch pots containing Metro Mix®350 and were allowed to grow in the greenhouse for an additional 22 daysat which time most plants contained 4-5 fully expanded leaves. Adevelopmentally uniform population of plant was selected from amongthese transplants and the individual plants were then sprayed with acarrier solution of AGWT (90.2% Acetone: 4.8% Glycerol: 4.8% Water:0.24% Tween 20 by volume) containing sulfonylurea compound 10015 atconcentrations of 1,4, or 16 grams/hectare (g/ha). The sprayed plantswere returned to the greenhouse and rated for injury 22 days later.

One to two days before spraying one leaf from each plant was frozen andstored at -80° C. for analysis of P450SU1 content. At assay thawedleaves were ground in a buffer containing 0.1M sodium tricine pH 7.8, 10mM sodium chloride, and 5 mM magnesium chloride. The extracts wereclarified by centrifugation at 28,000 to 33,000×g for one hour andprotein in the supernatant fraction was concentrated. The relativeP450SU1 content of the supernatant fraction from each leaf was estimatedby "immuno slot blots" where the extract from each leaf was placed in atemplate which deposited the extract onto individual "slots" or narrowlanes on nitrocellulose paper. The protein bound to the nitrocellulosewas incubated with a P450SU1 specific antibody and subsequently treatedas described for the Western Blot procedure.

Foliar application of 10015 at a rate of 1 g/ha (Table 18) resulted inminimal damage to nontransformed plants (W38) and the progeny of plantstransformed with plasmid pAGS112. In contrast, plants transformed withconstructions directing P450SU1 to the chloroplast (SSU-SU111.5,Cab-SU111.8, Cab-SU121.5 and Cab-SU131.5) were severely injured byapplication of compound 10015 at 1 g/ha. As shown in FIG. 14 damage tothe plants containing P450SU1 was indeed dramatic, resulting not only ina severe inhibition of plant growth but also in leaf chlorosis and grossmorphological deformation of new leaves arising near the shoot apex. Thedifference in height between the progeny of untransformed (W38) plantsand plants transformed with pAGS112 in FIG. 14 was within the range ofnormal variation expected following growout of untreated, transplantedtobacco plants.

Immuno slot blot analysis confirmed that injured plants contained theP450SU1 protein at the time of spraying. Two "exceptional" plants whichshowed lower than expected levels of injury contained either no(Cab-SU121.5-19) or lower (Cab-SU131.5-15) levels of P450SU1 thanseverely injured plants in the same family. These plants may besegregants containing no or single copies, respectively, of the geneencoding P450SU1. Control plants arising from pAGS112 primarytransformants were not individually typed for kanamycin resistance.However, since these plants segregated 3 resistant: 1 sensitive for theability to germinate on kanamycin, there is a >98% probability that atleast one plant transformed with pAGS112 was sampled at the optimaldiscriminatory rate of 1 g/ha 10015.

When this experiment was repeated at a higher application rate of 4 g/haof compound 10015, most plants transformed with constructions directingP450 SU1 to the chloroplast were again severely injured (Table 19).Nontransformed plants and progeny plants from a primary AGS112transformant showed some background damage at this higher applicationrate, but this damage was clearly less than that experienced by plantstransformed to contain chloroplast localized P450SU1. In this experimenttwo exceptional plants containing P450SU1 (Cab-SU111.8-10;Cab-SU131.5-21) exhibited lower than expected phytotoxic damage. Giventhat plants transformed with these plasmids and expressing P450SU1 wereseverely damaged at the lower application rate of 1 g/ha of compound10015 (Table 18), it is likely that these two exceptional plantsreceived a reduced dose of 10015 during treatment or were mistypedduring immuno slot analysis.

Several transformants containing cytoplasmically directed P450SU1(SU18.8, SU18.14) were damaged more severely than nontransformed plants,but to a lesser extent than transformants containing chloroplastlocalized P450SU1. This was especially evident at the treatment rate of4 g/ha of compound 10015 (Table 19). The difference in activity betweencytoplasmically localized and chloroplast localized P450SU1 does notalways reflect a higher accumulation of P450SU1 in the chloroplastdirected constructions (compare SU18.8, SU18.14 with Cab-SU111.8 andCab-SU121.5, Table 19). This suggests that P450SU1 functions moreefficiently in the chloroplast than in the cytoplasm.

When 10015 was applied at a concentration of 16 g/ha both transformedand non-transformed plants were extensively injured and no usefulinformation was obtained.

These data demonstrate that P450SU1 is functionally active in theprogeny of transformed plants at the whole plant level. In the case ofconstructions designed to direct the P450SU1 protein to the chloroplastthe inclusion of amino terminal extensions to P450SU1 as described inExample 19 did not prevent the activity of P450SU1 in intact plants.

                  TABLE 18                                                        ______________________________________                                        Response of P450SU1 Transformed Tobacco                                       to Sulfonylurea Compound 10015 (1 g/ha)                                       Family/  Plant     %         Protein Blot                                     Construction                                                                           I.D. No.  Damage    (ug/slot)                                                                             Rating                                   ______________________________________                                        W38                 0                NT                                       W38                 0                NT                                       W38                10                NT                                       AGS 112             0        10      (-)                                      AGS 112             0        10      (-)                                      AGS 112            10                NT                                       SU18.8   14        10        6       (++)                                     SU18.14  11        40        5       (++)                                     SSU-SU111.5                                                                            10        95        11      (++++)                                   SSU-SU111.5                                                                            22        95        10      (+++)                                    SSU-SU111.5                                                                            24        95                NT                                       Cab-SU111.8                                                                            12        90        9       (+)                                      Cab-SU111.8                                                                            14        95        4       (+)                                      Cab-SU111.8                                                                            17        95                NT                                       Cab-SU121.5                                                                            11        85                NT                                       Cab-SU121.5                                                                            13        95                (+)                                      Cab-SU121.5                                                                            18        95                NT                                       Cab-SU121.5                                                                            19        20        5       (-)                                      Cab-SU131.5                                                                            15        50        4       (+)                                      Cab-SU131.5                                                                            18        95        13      (++1/2)                                  Cab-SU131.5                                                                            27        90        11      (++)                                     ______________________________________                                         NT = Not Tested                                                               (+), (++), (+++), (++++) = relative amount of immunologically detected        P450SU1                                                                  

                  TABLE 19                                                        ______________________________________                                        Response of P450SU1 Transformed Tobacco                                       to Sulfonylurea Compound 10015 (4 g/ha)                                       Family/  Plant     %         Protein Blot                                     Construction                                                                           I.D. No.  Damage    (ug/slot)                                                                             Rating                                   ______________________________________                                        W38                0                                                          W38                10                                                         W38                20                NT                                       W38                30                NT                                       AGS 112            0                 NT                                       AGS 112            40                NT                                       SU18.8   11        60        6       (++)                                     SU18.14  15        70        6       (++)                                     SSU-SU111.5                                                                            11        100       13      (++++)                                   SSU-SU111.5                                                                            12        100       2       (+++)                                    SSU-SU111.5                                                                            13        100               NT                                       Cab-SU111.8                                                                            10        0         6       (+)                                      Cab-SU111.8                                                                            15        99        5       (+)                                      Cab-SU121.5                                                                            12        90        5       (+)                                      Cab-SU121.5                                                                            22        100       9       (+)                                      Cab-SU121.5                                                                            28        95                NT                                       Cab-SU131.5                                                                            21        40        12      (++)                                     Cab-SU131.5                                                                            28        100       13      (++)                                     Cab-SU131.5                                                                            29        100               NT                                       ______________________________________                                         NT = Not Tested                                                               (+), (++), (+++), (++++) = relative amount of immunologically detected        P450SU1                                                                  

EXAMPLES 22-25 Tissue Culture Growth of Transformed Tobacco Seed

Growth medium was prepared from Murishige minimal organics medium (GibcoLaboratories, Grand Island, N.Y.), 8 g/l agar, supplemented with Tvitamins (50 ppb biotin, 0.5 ppm pyridoxine HCl, 0.5 ppm thiamine HCl, 5ppm nicotinic acid, 0.5 ppm folic acid, 2 ppm glycine, 100 ppmmyo-inositol), sterilized and placed into sterile PlantCon plant tissueculture containers (Flow Laboratories, McLean, Va.). Tobacco seedobtained from the self-pollination of the primary transformants wassurface sterilized by a treatment of not more than 30 min in 20%chlorine bleach, 0.1% sodium dodecyl sulfate, followed by rinsing indistilled water, and placed on the surface of the medium in the sterilecontainers. Following this treatment, the seed was allowed to germinateand grow under illumination (100 microeinsteins·m⁻² ·s⁻¹), at 22° C.

Determination of the number of genetic loci of the transformed tobacco

The number of loci where t-DNA was incorporated into the genome of thetobacco was determined by segregation analysis of kanamycin resistancein the next generation of progeny. Seed from the self pollination of theprimary transformants was grown as described above on mediumsupplemented with 200 ppm kanamycin sulfate (Sigma). After 21 days,resistant (transformed) plants were unaffected compared to controlplants, whereas sensitive plants were smaller, partially chlorotic, andpoorly rooted. Determination of the number of genetic loci of theprimary transformants was based on the segregation of the kanamycinresistance trait.

EXAMPLE 22 Detection of the P-450 phenotype by sulfonylurea treatment

Because of the increased phytotoxicity of 10014 over that of 10015,plants grown in media containing 10015 should be growth inhibited ifthey contain an active cytochrome P450SU1. To test this, seeds oftobacco were grown in tissue culture media supplemented with 50 nMcompound 10015, and the results are shown in Table 20.

                  TABLE 20                                                        ______________________________________                                                        Number of                                                                     genetic                                                       Plant Line      loci.sup.a                                                                              Inhibition.sup.b                                    ______________________________________                                        AGS112 (Control)                                                                              1         1                                                   SU18.8          >2        1                                                   SU18.14         2         2                                                   SU18.15         >2        2                                                   SSU-SU111.5     ≧3 3                                                   Cab-SU111.8     >2        3                                                   Cab-SU121.5     2         3                                                   Cab-SU131.5     N.D..sup.c                                                                              3                                                   ______________________________________                                         .sup.a Number of genetic loci was determined by segregation analysis of       >100 seed                                                                     .sup.b Inhibition of growth of 6 individuals was visually rated. 1 =          little or no inhibition; 2 = moderate inhibition; 3 = severe inhibition,      cotyledons expand but no growth occurs.                                       .sup.c Number of genetic loci could not be determined.                   

The data in this table showed that plants containing the P450 gene,especially those where the mature protein is directed to thechloroplast, were sensitive to inhibition by compound 10015. The high(>1) number of genetic loci of most of the parents of these plantsinsures a high likelihood that all of the six plants sampled have theP450 gene.

Sulfonylurea Selection of P450+FeS containing Plants

The results above demonstrated that it was possible to use the P450 geneas a selectable marker by growing the plants in the presence of 50 nM ofcompound 10015. This technique was used to analyze the progeny of plantstransformed with both the gene for SU1 and FeS-B, and the results areshown in Table 21.

                  TABLE 21                                                        ______________________________________                                                    Kanamycin           Compound 10015                                Plant Line  Resistant Copy No.  Sensitive                                     ______________________________________                                        AGS502 (Control)                                                                          6/9       1         0/9                                           SuFe11.1    7/9       ≧4 2/9                                           SuFe11.3    5/10      1         0/8                                           SuFe11.4    7/10      1          0/10                                         SuFe11.7    9/10      1         0/9                                           SuFe11.8    10/10     2          1/10                                         SuFe11.11   7/8       2         0/9                                           SuFe21.2    7/10      1         7/9                                           SuFe21.5    8/10      1         8/9                                           SuFe21.6    9/10      1         7/9                                           SuFe21.7    7/10      1         5/7                                           SuFe21.8    8/9       1         10/10                                         ______________________________________                                    

Results for kanamycin resistance and compound 10015 sensitivity areexpressed as plants demonstrating result/total plants. Copy numberdetermination is from kanamycin sensitive segregation analysis of about100 seed.

Plants exhibiting sensitivity to compound 10015 could be rescued fromthis treatment by plucking the seedlings from the surface of the mediumand placing them in fresh medium containing no 10015. After severalweeks growth, leaf tissue from the plants was collected, homogenized andanalyzed for presence of the cytochrome P450SU1 antigen by Western blotanalysis. Analysis of both 10015 resistant and 10015 sensitive plantsfrom lines SuFe21.2, SuFe21.5, SuFe21.6, SuFe21.7, and SuFe21.8 revealedthat of 8 plants characterized as 10015 resistant none had detectablelevels of P450SU1 on a Western blot, while 18 out of 21 plants sensitiveto 10015 had Western blot detectable levels of P450SU1.

These results demonstrated that the expression of P450SU1 leads to anegative selectable phenotype. When the mature protein was targeted tothe chloroplast, this selection as comparable to the positive selectionby kanamycin.

EXAMPLE 23 Sulfonylurea Selection of Transgenic Tobacco Lines SuFe31 andSuFe41

Plants transformed with the plasmids pSuFe31 and pSuFe41 were selectedfor high expression of P450SU1 and FeS-B mRNA by primer extensionanalysis as described in Example 19, and self pollenated to produceseed. This seed was germinated on medium containing 50 nM of compound10015 and analyzed for sensitivity to this compound (indicating thepresence of an active cytochrome P450SU1 enzyme) as in Example 22.

                  TABLE 22                                                        ______________________________________                                                    Number                 Ratio                                      Plant       10015      Number 10015                                                                              Sensitive/                                 Line        Resistant  Sensitive   Resistant                                  ______________________________________                                        AGS502 (Control)                                                                          32         0           0                                          SuFe31.13    4         12          3.0                                        SuFe31.28    5         10          2.0                                        SuFe41.34   32         0           0                                          SuFe41.37    8         24          3.0                                        SuFe41.56   32         0           0                                          SuFe41.60   15         0           0                                          ______________________________________                                    

Segregation of the compound 10015 sensitivity trait in SuFe31.13,SuFe31.28 and SuFe41.37 demonstrates that the sensitive plants areexpressing an enzymatically active cytochrome P450SU1, and these plantsare progeny of a heterozygous plant transformed at a single locus.

EXAMPLE 24 Transformed Tobacco Detoxification of Sulfonylurea

Tobacco seed from plants transformed with several P450SU1 andP450SU1+FeS-B constructions were tested for their ability to grow ontissue culture medium supplemented with compound 10001. Seed was placedon medium containing: 0, 5, 10, 20, and 40 nM of compound 10001. After100 days the plants were visually rated for their resistance (due toherbicide detoxification) to the herbicide treatment. All plants grownin the absence of herbicide and those treated with the lowest levels (5nM and 10 nM) of 10001 had grown so large that no comparative rating waspossible. The severely growth inhibited plants (those grown in thepresence of 20 nM and 40 nM of compound 10001) were scored by comparingthem to AGS502 plants (transformed without P450 gene) in Table 23.

                  TABLE 23                                                        ______________________________________                                                   10001             Individual                                       Plant Line Concentration (nM)                                                                              Scores                                           ______________________________________                                        SuFe21.5   20                2,0,0,0,0,0                                      SuFe21.5   40                3,3,3,2,1                                        SuFe21.8   20                3,3,0,0,0                                        SuFe11.8   20                0,0,0,0,0                                        SuFe11.8   40                0,0,0,0,0,0                                      SuFe11.4   20                3,3,2,0,0                                        SuFe11.4   40                0,0,0,0,0,0                                      SSU-SU111.5                                                                              20                0,0,0,0,0                                        SSU-SU111.5                                                                              40                0,0,0,0                                          ______________________________________                                         SCORING SYSTEM: Visual comparison to AGS502 plants which uniformyl            appeared:                                                                     20 nM ˜1 cm tall, 6 leaves ˜1 cm diameter                         40 nM ˜0.5 cm tall, 6 leaves ˜0.3 cm diameter, chlorotic          Ratings:                                                                      0 = essentially identical to AGS 502 controls;                                1 = marginally larger (≧1.2×) than AGS502;                       2 = clearly larger (1.2 to 2×) than AGS502;                             3 = substantially larger (>2×) than AGS502.                        

EXAMPLE 25 Interchangeability of FeS-A and FeS-A

The ability of both FeS-A or FeS-B to transfer reducing equivalents toeither P450SU1 or P450SU2 was examined. Mixtures of the purifiedproteins were tested to see if FeS-A and/or FeS-B carried out thetransfer of electrons from NADPH and Spinach ferredoxin:NADPoxidoreductase to cytochromes P450SU1 or P450SU2. The ability for theseFeS proteins to transfer reducing equivalents is a prerequisite fortheir involvement in the catalytic activity of the cytochromes P450.

The experiment was carried out at room temperature, in a bufferconsisting of 0.1M MOPS-NaOH (pH 7.0), 0.2M NaCl, 10 mM compound 10013(chlorosulfuron), and 50 nM ferredoxin:NADP oxidoreductase (purifiedfrom spinach leaves according to the method of Zanetti and Curti,Methods in Enzymology, 1980, Vol 69, pp250-255, herein incorporated byreference). To this mixture was added either FeS-A or FeS-B (asindicated in Table 24, 0.03 mM NADPH, and incubated for 10 min. Theabsorption spectrum was measured (Hewlett-Packard Model 8450A uv/visspectrophotometer), P450 protein added, the sample bubbled with CO for30 seconds, and the absorption measured again after 1 min and 5 min. Theappearance of an absorption band at about 450 nm indicated the reductionof the cytochrome by the FeS protein.

                  TABLE 24                                                        ______________________________________                                                       Fraction P450                                                                             Fraction P450                                      Additions.sup.a                                                                              Reduced 1 min                                                                             Reduced 5 min                                      ______________________________________                                        P450SU1        <0.05       <0.05                                              P450SU1 + FeS-A                                                                              0.51        0.81                                               P450SU1 + FeS-B                                                                              0.10        0.46                                               P-450SU2       <0.05       <0.05                                              P450SU2 + FeS-A                                                                              0.98        1.0                                                P450SU1 + FeS-B                                                                              0.91        1.0                                                ______________________________________                                         .sup.a Proteins were added at concentrations defined by their absorption      spectra: SU1 (A418 = 0.017), SU2 (A418 = 0.027), FeSA (A410 = 0.066), FeS     (A410 = 0.071).                                                          

The data in Table 24 demonstrated that the FeS proteins participate inthe transfer of electrons to the cytochrome P450, and that they may beused interchangeably, either FeS-A or FeS-B with SU1, or either FeS-A orFeS-B with SU2.

EXAMPLE 26 A negative selection system in transgenic Arabidopsis

Shoot growth of Arabidopsis seedlings that carry the cytochrome P450SU1coding region was arrested when seeds were germinated on mediumcontaining the sulfonylurea 10015 at concentrations which have novisible effect on seedlings lacking the coding region, thus providing anegative selection system for plants expressing the introduced gene.Plants lacking expression of the gene survived, while shoot growth ofthose expressing the gene was stunted.

The plasmids pSU18, pSSU-SU111, and pCab-SU111, as described in Example19, Section C, were transformed directly into the Agrobacterium strainLBA4404/pAL4404 (Hoekema et al. Nature 303:179-180, 1983) using thefreeze-thaw method (Plant Molec. Biol. Manual, S. B. Gelvin and R. A.Schilperoot, editors, A3:1-19, 1988, herein incorporated by reference)and selected on YEP medium (Table 25) with 50 mg/l rifampicin and 5 mg/ltetracycline. The presence of the plasmid DNA in selected clones wasverified by restriction digests.

Standard aseptic techniques for the manipulation of sterile media andaxenic plant/bacterial cultures were followed, including the use of alaminar flow hood for all transfers. Compositions of the culture mediaare listed in Table 25. Unless otherwise indicated,, 25×100 mm petriplates were used for plant tissue cultures. Incubation of plant tissuecultures was at 23° C. under constant illumination with mixedfluorescent and "Gro and Sho" plant lights (General Electric) unlessotherwise noted.

The source of explants was in vitro grown plants of Arabidopsis thaliana(L.) Heynh, geographic race Wassilewskija. Seeds were sterilized for 10min in a solution of 50% chlorine bleach with 0.1% sodiumdodecylsulfate, rinsed three to five times with sterile distilled H₂ O,dried thoroughly on sterile filter paper, and then sown on GM medium.The plates were sealed with filter tape (Carolina Biologicals,Burlington, N.C. U.S.A.) and incubated for seven days as describedabove. Seedlings were transferred to GM medium in 25×150 mm petridishes, 36-40 per plate. Plates were sealed with filter tape andincubated for 2-3 weeks.

Prior to inoculation with Agrobacterium, root tissues were cultured oncallus induction medium (MSKig) for four days. Whole root systems wereharvested by pulling plantlets out of the agar using forceps, laying theroots on MSKig medium, and then cutting off the shoot with a scalpel.Petri dishes were sealed with filter tape and incubated for four days.

Cultures of Agrobacterium cells containing each of the plasmids weregrown in 5 ml of YEP broth containing 2 mg/l tetracycline. The cultureswere grown for approximately 17-20 hours in glass culture tubes in a NewBrunswick platform shaker (225 rpm) maintained at 28° C. Pre-culturedwhole roots were cut into 0.5 cm segments and placed in a 100 μm filter,made from a Tri-Pour beaker (VWR Scientific, San Francisco, Calif.U.S.A.) and 100 μm wire mesh, which is set in a petri dish. Rootsegments were inoculated for several minutes in 30-50 ml of a 1:20dilution of an overnight Agrobacterium culture with periodic gentlemixing. Inoculated roots were transferred to sterile filter paper todraw off most of the liquid. Small bundles of roots, consisting ofseveral root segments, were placed on MSKig medium containing 100 μmacetosyringone (3',5'-dimethoxy-4'-hydroxyacetophenone, Aldrich ChemicalCo., Milwaukee, Wis. U.S.A.). Petri plates were sealed with parafilm orfilter tape and incubated for two to three days.

After inoculation, root segments were rinsed and transferred to shootinduction medium containing antibiotics. Root bundles were placed in a100 μm filter unit (described above) and rinsed with 30-50 ml liquidMSKig medium. The filter was vigorously shaken in the solution to helpremove the Agrobacterium, transferred to a clean petri dish, and rinsedagain. Roots were blotted on sterile filter paper and bundles of rootswere placed on MSg medium containing 500 mg/l vancomycin with andwithout 50 mg/l kanamycin. Plates were sealed with filter tape andincubated for 12 to 21 days.

Green nodules and small shoot primordia were visible at about 2 weeks.The explants were either left intact or were broken into numerous piecesand placed on GM medium containing 200-300 mg/l vancomycin for furthershoot development. Plates were either sealed with two pieces of tape orwith filter tape. As they developed, individual shoots were isolatedfrom the callus and were placed on MSRg medium containing 100 mg/lvacomycin. Dishes were sealed as descried above and incubated for fourto seven days. Shoots were then transferred to GM medium containing100-200 mg/l vacomycin in 25×100 mm petri dishes or PlantCon containers(Flow Laboratories, McLean. Va.). Many primary transformants (T1) whichwere transferred to individual containers set seed (T2).

T2 seed was harvested from selected putative transformants and sown onGM medium containing 50 mg/l kanamycin and that containing 5 ppb 10015.Plates were sealed with filter tape, cold treated for 2 or more days at4° C., and then incubated for 10 to 20 days at 23° C. under constantillumination as described above. Seedlings were scored as resistant(green, true leaves develop) and sensitive (no true leaves develop).Table 26 shows the number and percent of seedlings that are resistantand sensitive to kanamycin and 10015. The percent of resistant seedlingsis inversely proportional with the two selections. Kanamycin is apositive selection for those seedlings that carry the foreign DNA.Therefore, this inverse relationship indicated that 10015 negativelyselected, that is arrested shoot growth of, seedling expressing theP450SU1 gene, while those seedlings that do not express the P450SU1 genesurvived.

Selected T2 seedlings that were kanamycin resistant were transplanted tosoil and were grown to maturity at 21° C. daytime (14 hours) 18° C.nighttime (10 hours) at 65-80% relative humidity. T3 seed was collected,sterilized, and germinated on GM medium containing 50 mg/l kanamycin andthat containing 5 ppb 10015. Plates were sealed with filter tape, coldtreated for 2 or more days at 4° C., and then incubated for 10 to 20days at 23° C. under constant illumination as described above. Seedlingswere scored as resistant and sensitive and results are shown in Table27. Two of the six plants produced seed that was 100% resistant tokanamycin and 100% sensitive to 10015; they are homozygous for theinserted DNA. The other four parents are heterozygous and show aninverse proportion of kanamycin and 10015 resistant seedlings. Thus,growth of seedlings which carry the heterologous genes was arrested whengrown on medium containing 10015, while growth of seedlings which do notcarry the genes was not affected. Therefore, seedlings expressing theP450SU1 gene can be negatively selected.

Selective destruction of plant tissues was exhibited in seedlings grownon medium containing 10015. Expression of the P450SU1 gene wascontrolled by the tissue-specific promoter from the cab gene which isexpressed in the green tissues of plants. T3 seedlings grown on 5 ppb10015, as described above, exhibited root growth but shoot growth wasinhibited. Thus, only the shoot, which expresses P450SU1 was destroyedby the application of 10015.

Germination assays of homozygous seed on various concentrations of 10015were performed to assay the relative sensitivity to 10015 produced bythe three different promoters and between independent transformants.Seed was sterilized, sown on GM medium with 0. 0.5, 1, 2, 5, 10 and 20ppb 10015, incubated, and scored as described above. In addition,seedlings are rated on a scale of one to three for the amount of growth.Results are shown in Table 27A. These results shown that independenttransformants exhibit different sensitivity to 10015.

To test if seedlings that do not carry the cytochrome P450SU1 codingregion or those that exhibit lower activity of the gene product can beselected, wild type seeds were placed in specified areas on GM mediumcontaining 10 ppb 10015. Over 500 seed that are homozygous for theP450SU1 coding region were sown on the same plates. The plates weresealed, cold-treated, and incubated as previously described. Plates wereobserved to determine if differentiation exists between the wild typeseeds, and those exhibiting activation of 10015. Wild type seedlingswere unaffected by the dying transformed seedlings. In addition, whengreater than 10,000 seed of a homozygous Cab-SU111 plant was sown on GMmedium with 10 ppb 10015, then cold-treated and incubated as describedabove, eighteen seedlings were resistant to 10015 and were unaffected byneighboring seedlings.

Integration of the coding region is confirmed by Southern blot analysisof selected progeny exhibiting kanamycin resistance and 10015sensitivity. Southern blots are performed as described in Sambrook etal., Molecular Cloning: A Laboratory Manual 2nd edition (Cold SpringHarbor Laboratory, New York, 1989) hereby incorporated by reference.Plant DNA is digested with an enzyme appropriate for producing a DNAfragment containing DNA sequence from the introduced DNA, and anappropriate probe is used to detect this fragment.

                  TABLE 25                                                        ______________________________________                                        Medium Composition                                                            YEP MEDIUM       Per Liter                                                    ______________________________________                                        Bacto Yeast Extract                                                                            10.0 g                                                       Bacto Peptone    10.0 g                                                       NaCl              5.0 g                                                       Agar (optional)  15.0 g                                                       pH 7.0                                                                        ______________________________________                                        BASIC MEDIUM                                                                  1 pkg. Murashige and Skoog Minimal Organics Medium                            without Sucrose (Gibco #510-3118 or Sigma # M6899)                            10 ml Vitamin Supplement                                                      0.05% MES                                                                     0.8% agar                                                                     pH 5.8                                                                        VITAMIN SUPPLEMENT - 100 × Stock                                        10 mg/l thiamine                                                              50 mg/l pyridoxine                                                            50 mg/l nicotinic acid                                                        GM = Germination Medium                                                       Basic Medium                                                                  1% sucrose                                                                    MSKig = Callus Induction Medium                                               Basic Medium                                                                  2% glucose                                                                    0.5 mg/l 2,4-D                                                                0.3 mg/l Kinetin                                                              5 mg/l IAA                                                                    MSg = Shoot Induction Medium                                                  Basic Medium                                                                  2% glucose              20     g/l                                            0.15 mg/l IAA           0.86   uM                                             5.0 mg/l 2iP            24.6   uM                                             MSRg = Shoot Induction Medium                                                 Basic Medium                                                                  2% glucose              20     g/l                                            12 mg/l IBA             58.8   uM                                             0.1 mg/l Kinetin        0.46   uM                                             ______________________________________                                    

                  TABLE 26                                                        ______________________________________                                        Seed Germination Assay                                                                   Kanamycin   10015                                                             (50 mg/l)   (5 ppb)                                                ID    Plasmid    #R.sup.a                                                                             #S.sup.b                                                                           % R.sup.c                                                                           #R.sup.a                                                                           #S.sup.b                                                                           % R.sup.c                        ______________________________________                                        12-1  pCab-SU111 11     6    65    3    10   23                               12-2  pCab-SU111 0      12   0     13   0    100                              12-4  pCab-SU111 13     18   42    12   8    60                               12-5  pCab-SU111 0      20   0     15   0    100                              12-6  pCab-SU111 15     9    62    5    9    36                               12-7  pCab-SU111 21     7    75    9    13   40                               12-8  pCab-SU111 6      5    55    1    7    13                               12-9  pCab-SU111 13     3    81    3    9    25                                12-10                                                                              pCab-SU111 0      21   0     9    0    100                               12-11                                                                              pCab-SU111 0      9    0     4    0    100                              ______________________________________                                         .sup.a = number of resistant seedlings                                        .sup.b = number of sensitive seedlings                                        .sup.c = percent of seedlings which are resistant                        

                  TABLE 27                                                        ______________________________________                                        T3 Seed Germination Assay                                                                Kanamycin   10015                                                             (50 mg/l)   (5 ppb)                                                ID    Plasmid    #R.sup.a                                                                             #S.sup.b                                                                           % R.sup.c                                                                           #R.sup.a                                                                           #S.sup.b                                                                           % R.sup.c                        ______________________________________                                        12-1-1                                                                              pCab-SU111 184     0   100    0   196   0                               12-1-2                                                                              pCab-SU111 191     0   100    0   191   0                               12-1-3                                                                              pCab-SU111 136    41   77    42    90  32                               12-1-4                                                                              pCab-SU111  98    39   72    80   129  37                               12-1-5                                                                              pCab-SU111 161    56   74    99   177  36                               12-1-6                                                                              pCab-SU111 254    75   77    83   152  35                               WT    --          0     77    0    58    5   92                               ______________________________________                                         .sup.a = number of resistant seedlings                                        .sup.b = number of sensitive seedlings                                        .sup.c = percent of seedlings which are resistant                        

                  TABLE 27A                                                       ______________________________________                                                     Visual Inhibition Ratings                                                     of Seedlings*                                                                 ppb 10015                                                        ID       Construct 0      1    2    5    10   20                              ______________________________________                                        Wild type          1      1    1    1    1    1                               12.20.5  Cab-SU111 1      2    2    3    4    4                               12.1.1   Cab-SU111 1      1    1    2    4    4                               12.16.2  Cab-SU111 1      1    1    1    1    1                               17.74.4  SSU-SU111 1      1    1    2    3    3                               13.4.6   SSU-SU111 1      1    1    3    4    4                               17.92.3  SSU-SU111 1      1    1    1    1    1                               17.17.3  SU18      1      1    --   1    2    4                               13.3.1   SU18      1      1    1    2    4    4                               17.1.10  SU18      1      1    1    3    4    4                               ______________________________________                                         *Scale of 1 to 4 with 4 = complete inhibition, and 1 = no inhibition.    

EXAMPLE 27 Cytochrome p450SU1 metabolism of sulfonylureas supported byvarious FeS proteins

the purpose of this example was to define the combination of cytochromep450SU1 and other proteins which results in optimal metabolism ofsulfonylureas, based on conclusions from in vitro experiments. In theseexperiments, the rate of metabolism of 10015 to 10014, mediated bypurified cytochrome p450SU1, was tested to find which FeS proteinfunctions as the best direct electron donor.

Assays were carried out in 0.025 ml of buffer containing 0.1M MOPS-NaOH(pH 7.0), 0.2M NaCl, 0.2 mM 10015, 2 μM purified cytochrome p450SU1,Spinach Ferredoxin:NADP oxidoreductase (FNR) as indicated in Table 28,various FeS proteins as indicated in Table 28, and an NADPH regeneratingsystem consisting of 5 mM glucose-6-phosphate, and 2 Units/mlLeuconostoc mesenteroides glucose-6-phosphate dehydrogenase. Thereaction was initiated by the addition of NADPH to a final concentrationof 0.03 mM. After 15 min the reaction was terminated by the addition of0.25 ml H₂ O-acetonitrile:H₃ PO₄ (80:19:1). After filtering this mixturethrough a 0.2 μm filter, the amount of metabolite (10014) formed wasanalyzed by HPLC.

                  TABLE 28                                                        ______________________________________                                                        FNR      Rate                                                                 concen-  (nmol 10014) ·                              FES             tration  (nmol p450)-1 ·                             Addition        (mM)     (min)-1                                              ______________________________________                                         4 mM FeS-B     0.2      0.3                                                   4 mM FeS-B     2.0      0.3                                                  20 mM FeS-B     2.0      0.4                                                   4 mM FeS-A     0.2      1.0                                                   4 mM FeS-A     2.0      2.6                                                  20 mM FeS-A     2.0      5.1                                                   4 mM spinach Fd                                                                              0.2      0.2                                                   4 mM spinach Fd                                                                              2.0      0.2                                                  20 mM spinach Fd                                                                              2.0      0.4                                                  none            0.2      <0.03                                                none            2.0      0.06                                                 ______________________________________                                    

These results demonstrated that FeS-A, FeS-B, and spinach ferredoxin (anFeS protein) functioned as the direct reductant of P450SU1 during 10015metabolism. Because a 10-fold increase in the FNR concentration did notincrease the rate of metabolism with FeS-B or spinach ferrodoxin, it wasapparent that FNR was not rate limiting for those reactions, and theoverall rate of metabolism was determined by FeS reduction of the P450.At 2 μM FNR, although somewhat rate limited by FNR, the rate ofmetabolism when 4 μM FeS-A was present was still at least 8-fold fasterthan with the same concentration of FeS-B.

It is not known if this differential ability of the two S. griseolus FeSproteins to support sulfonylurea metabolism was a result of some damageto FeS-B occurring during purification, or if the same differentialability occurs in vivo with the endogenous reductase proteins.Nonetheless, these in vitro results suggested than p450SU1 and FeS-Awere the optimal combination for maximal p450SU1 metabolic activity, andsupported claims for combinations of DNA resulting in coordinatedexpression of these two proteins as preferred constructions.

EXAMPLE 28

the cytochrome p450SU1 coding region was expressed specifically in theanther tissue of tobacco plants. The promoter region derived from thetobacco TA29 gene, which is a gene expressed naturally only in thetapetal tissue of the tobacco anther, was used. The tobacco TA29 genehas been described by Goldberg in Science 240, pp. 1460-1467 (1988) andin EPA 89-344029. The TA29 promoter fragment was prepared from the TA29gene by isolating a 1500 bp ClaI-HindIII fragment from the TA29 geneclone, during which the ClaI end was filled in, and cloning this intothe HincII (blunt) and HindIII sites of M13mp19. The sequence of DNAsurrounding the translation initiation ATG was determined by sequencingin from the HindIII end of the fragment according to the method ofSanger et al., Proc. Natl. Acad. Sci. U.S.A. 74:5463-5467 (1977) using aU.S. Biochemical Corporation Sequenase DNA sequencing kit and followingthe manufacturer's protocol. It was then altered to create an NcoI siteat this ATG by using site-directed mutagenesis, as described in Viitanenet al., J. Biol. Chem. 263:15000-15007 (1988). The mutagenesis wascarried out using the oligonucleotide of sequenceAGAAATTAGCTACCATGGTAGCTCCAAAAT that was synthesized using an AppliedBiosystems DNA synthesizer and following the manufacturer's procedure.The TA29 promoter fragment containing the new NcoI site was then movedas a SmaI-HindIII fragment, the SmaI site being derived from the M13mp19polylinker, into SmaI and HindIII digested pTZ19 (Pharmacia) creatingpTZAL.

Two chimeric genes were constructed that contain the TA-29 promoter andthe SU1 coding region followed by the petunia Rubisco small subunit geneuntranslated and polyadenylation region ("SSU301'"). One chimeric genealso contained the Rubisco small subunit chloroplast transit sequenceand the other did not. These chimeric genes were called A-T-SU1 andA-SU1, respectively. To construct A-SU1 a ScaI-BamHI fragment wasisolated that contains the same SU1 coding region and "SSU301"polyadenylation region that was present in the clone pSU17 which hasbeen deposited with the ATCC and bears accession number 67995. The ScaIend of the fragment was joined to the filled in NcoI site at the 3' endof the TA29 promoter. The plasmid containing the TA29 promoter fragmentwas also digested with BamHI to accommodate the 3' end of the SU1fragment. The resulting plasmid was called pTZA-SU1.

In constructing A-T÷SU1 the source of the SU1 coding region adjacent tothe transit sequence was the SSu-SU11 gene which has been deposited withthe ATCC as pSSU-SU11 and bears the accession number 67994. An NcoIfragment containing the transit sequence and the 5' region of SU1 waspurified as well as an NcoI-HindIII fragment containing the 3' region ofSU1 and some polyadenylation region from the SSU301 gene. TheNcoI-HindIII 3' fragment was first ligated with NcoI and HindIII cutpTZAL that was described above. Next the NcoI fragment was ligated intothe NcoI site of the resulting plasmid and a clone containing thisfragment in the correct orientation was identified by digestion withSphI. From the resulting clone a SmaI-DraI fragment containing the TA29promoter, transit sequence, and part of the SU1 coding region was clonedinto SmaI and DraI digested pTZA-SU1, the SmaI site in both beingpresent in the pTZ19 polylinker. This step was carried out to place thepromoter, transit, and 5' SU1 sequences adjacent to a complete SSU301polyadenylation region. The resulting plasmid was called pTZA-T-SU1.

The SU1 chimeric genes were each isolated as Asp718-BamHI fragments, theAsp718 site coming from the polylinker of pTZ19. They were ligated intoAsp718 and BamIII digested pZS96. pZS96 was prepared as described inExample 19. The resulting plasmid with the A-SU1 chimeric gene residingin the pZS96 plasmid was pZ6A-SU1 and is shown in FIG. 25A. Theresulting plasmid with the A-T-SU1 chimeric gene residing in the pZS96plasmid was called pZ6A-T-SU1 and is shown in FIG. 25B.

pZ6A-SU1 and pZ6A-T-SU1 were each transformed in Agrobacteriumtumefaciens strain LBA4404 by direct DNA uptake following the proceduredescribed in Plant Molecular Biology Manual, S. B. Gelvin et al., eds.Kluwer Academic Press PMAN-A3/7, 1988, herein incorporated by reference.The presence of each intact vector in Agrobacterium colonies selected onminA medium with sucrose containing 100 μg/ml kanamycin and 100 μg/mlcarbenicillin was verified by restriction enzyme digests of miniprepDNA. Leaf disks of Nicotiana tabacum cv. Xanthi were inoculated withAgrobacterium carrying the constructed plasmids and kanamycin resistantplants were obtained as described previously.

Twenty-one plants transformed with the A-T-SU1 gene and 15 plantstransformed with the A-SU1 gene were grown to maturity. From each plant,anthers were dissected from five early developmental stage buds in whichthe petals had not yet separated and they were frozen in liquidnitrogen. RNA was prepared following the procedure of Verwoerd et al.,Nucleic Acids Research 17:2362, 1989, and analyzed on Northern blots forthe presence of messenger RNA (mRNA) produced by the chimeric SU1 genethat was introduced into the plant. Northern blots were preparedaccording to Rave et al. Nucleic Acids Research 6:3559-3569, 1979, andprobed as described in Maniatis et al. Molecular Cloning: a LaboratoryManual, Cold Spring Harbor, N.Y., each herein incorporated by reference.The probe fragment used was a PstI fragment isolated from SSU-SU114containing part of the transit sequence and the SU1 coding region. Thisprobe detected the A-SU1 and A-T-Su1 mRNAs as well as the Rubisco smallsubunit mRNA (due to homology with the transit sequence).

In several plants no SU1 mRNA was detected in the anthers and theseplants were not analyzed further. Plants showing expression of the SU1mRNA in the anthers were analyzed further to determine whether the SU1mRNA expression was anther-specific. Leaf RNA was prepared from eachplant and compared to the anther RNA isolated from the same plant onNorthern blots. The levels of SU1 mRNA in the leaf and anther RNAsamples from each plant were compared to distinguish those plants inwhich the anther SU1 mRNA was in greater abundance than the leaf SU1mRNA, indicating anther-specific expression. "Anther-specific" as usedherein means expression of the gene regulated by the anther-specificpromoter is predominantly in the desired anther tissue. Out of 14 plantsexpressing the A-T-SU1 mRNA in the anther, 71% showed anther-specificexpression. The term "anther" refers to the part of the flower thatphysically contains pollen. Pollen grains, at all stages of development,are considered a part of the anther. For the sake of simplicity, theterm is intended to include gamete as well. By "gamete" is meant amature germ cell capable of forming a new individual by fusion withanother gamete. Out of 12 plants expressing the A-SU1 mRNA in theanther, 42% showed anther-specific expression. Thus there was somevariability among plants receiving the SU1 coding region regulated bythe TA29 promoter, but plants with anther-specific expression of thep450SU1 gene were created.

The resulting data were as follows:

    ______________________________________                                        A denotes anther, L denotes leaf                                              ______________________________________                                        A-T-SU1 plants:                                                                             A>>L: 17A, 33A, 41A, 43A, 56A                                                 A>L: 13A, 24A, 28A, 31B, 38A                                                  A=L: 61A, 63A, 64B                                                            A<L: 52B                                                                      no A: 7A, 12A, 23A, 37A, 59A,                                                 62B                                                                           plant 65A produced no buds                                      A-SU1 plants: A>>L: 19A, 31A, 34A                                                           A>L: 26A, 56A                                                                 A=L: 36C, 52A, 59A                                                            A<L: 11B, 32A, 40A, 64B                                                       no A: 3A, 8A                                                                  plant 14A produced no buds                                      ______________________________________                                    

Application of compound 10015 was as follows. The tapetal cells of theanther surround the developing pollen and are instrumental in supportingthe development of mature pollen. Thus production of a toxin in thetapetal cells was expected to disrupt the development of normal maturepollen. The nontoxic compound 10015 was sprayed onto floweringtransgenic plants that had anther-specific expression of P450SU1 mRNA.Plants were hand sprayed with rates between 4 and 128 g/hectare, whichconsisted of 14-25 ml of 5.3-95 μg/ml of 10015. The 10015 was firstdissolved in up to 0.8 ml of 0.01N ammonium hydroxide and then dilutedinto AGWT (90.2% Acetone: 4.8% Glycerol: 4.8% Water: 0.24% Tween 20 byvolume). Little effect was seen when rates of less than 32 g/ha wereapplied. At 32 g/ha and above, effects were seen on the ability ofpollen to germinate in vitro. Newly opened buds were collected at timeintervals between four and 23 days after spraying. The anthers wereremoved and pollen was brushed into Brewbaker and Kwak medium (15%sucrose, 200 ppm calcium nitrate, 100 ppm boric acid). Growth of tubesfrom the pollen, indicating germination, was assessed after four hoursof incubation by microscopic observation.

Pollen from some of the transgenic plants collected followingapplication of 10015 showed reduced ability to germinate in vitro.Germination of pollen from two plants with anther-specific expression ofthe A-T-SU1 gene (41A and 56A) was reduced to 0% at 7 to 11 days afterapplication of 32 g/ha of 10015 (0.59 mg in 20 ml). The germinationstayed at less than 0.1% through 18 days on one of these plants andthrough 13 days on the other plant. Three other plants (31B, 43A, 24A)also had reduced pollen germination rates varying between 0 and 2% fortime periods of a few days to a week. Pollen from the controluntransformed plant with the same application of 10015 germinated at arate of 50% to 90% (varying between buds) over this same time period.Two other transgenic plants sprayed with 100 g/ha (1.85 mg in 24 ml)were greatly affected: one (plant 28A) had no pollen germination at 7-14days after treatment and less than 0.1% germination at 21 days, theother (plant 38A) had no pollen germination at 7-11 days, but increasedto 1-25% (varying between buds) at 14 days. Thus seven plants out of the10 plants tested that had anther-specific expression of A-T-SU1 showedreduced pollen viability in vitro following application of 10015, andthree plants showed almost complete absence of pollen viability for aweek or more.

The transgenic plants expressing the A-SU1 gene were not as affected by10015 application: two plants showed only slight reduction in pollenviability.

Thus it has been demonstrated by an in vitro pollen germination assaythat application of 10015 to transgenic plants, that express the p450SU1gene from the TA29 promoter and shown anther-specific expression of thep450SU1 mRNA, substantially reduced the viability of the pollen. Theability of pollen from treated plants to function in vivo is beingtested by using it to cross fertilize emasculated flowers on controluntreated plants. The female fertility of treated plants is being testedby cross-fertilizing emasculated flowers of these plants with pollenfrom untreated control plants. It is expected that the three plants thatwere most affected by the 10015 application as described above willbehave as male sterile, female fertile plants in the time period whenthe in vitro pollen germination is lowest.

EXAMPLE 29 Metabolism of Non-sulfonylurea Herbicides by BacteriaContaining the Genes for p450SU1

This experiment was performed as in Example 17 with the followingchanges. Separate cultures (50 ml) inoculated with S. lividans C37, S.lividans transformed with pCAO200SU1-FeS-B#9, or S. griseolus ATCC11796were cultured in sporulation broth for 18 hours at 30° C. with shaking.Each culture was then resuspended in 25 ml fresh sporulation broth and3.0 mg herbicide added. Each culture was reincubated for 18 hours, thenan aliquot of the medium was withdrawn and analyzed by HPLC. The percentconversion of herbicide was determined.

The percent conversion of herbicide is presented in Table 29. Theresults in Table 29 show that bacteria containing constitutivelyexpressed P450SU1 metabolized the nonsulfonylurea herbicides 10033,10034, 10035, and 10036.

                  TABLE 29                                                        ______________________________________                                                   Percent Conversion                                                 Strain       10033    10034    10035  10036                                   ______________________________________                                        S. griseolus 100      13       21     100                                     ATCC11796                                                                     S. lividans C37                                                                             5       10       22      8                                      S. lividans pCAO200                                                                        88       69       96     100                                     SU1-FeS-B#9                                                                   ______________________________________                                    

What is claimed is:
 1. An isolated DNA molecule encoding cytochrome P450enzyme P450SU1 and iron sulfur protein FeS-B comprising ##STR7##
 2. Anisolated DNA molecule encoding cytochrome P450 enzyme P450SU1 comprising##STR8## ##STR9##
 3. A sequence of DNA encoding cytochrome P450 enzymeP450SU2 and iron sulfur protein FeS-A comprising ##STR10## ##STR11####STR12##
 4. An isolated DNA molecule encoding cytochrome P450 enzymeP450SU2 comprising ##STR13##
 5. The isolated DNA molecule of claims 2 or4 which when transformed into bacteria or plants causes metabolism ofsulfonylurea compounds.
 6. The isolated DNA molecule of claim 2 whichwhen transformed into bacteria or plants causes metabolism of theherbicide3-cyclohexyl-1-methyl-6-dimethylamino-S-triazine-2,4(1H,3H)dione;4-amino-6-tert-butyl-3-(methylthio)-AS-triazin-5(4H)one;3-(3-chloro-p-tolyl)-1,1-dimethylurea;N-(2-chloro-6-methylphenyl)-5,7-dimethyl-1,2,4-triazolo-1,5A-pyrimidine-2-sulfonamide;2-[(4,5-dihydro-4-methyl-4-(1-methylethyl)-1H-imidazol-2-yl)]-5-ethyl-3-pyridinecarboxykicacid;2-[(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylicacid; or N-(2,6-dichlorophenyl)-4,6-dimethyl-2-pyrimidinesulfonamide. 7.The sequence of claim 4 which when transformed into bacteria or plantscauses metabolism of theherbicide3-cyclohexyl-1-methyl-6-dimethylamino-S-triazine-2,4(1H,3H)dione;4-amino-6-tert-butyl-3-(methylthio)-AS-triazin-5(4H)one;7-chloro-5-fluoro-4-(2,3,4,5,6,7-hexahydro-1,3-dioxo-1H-isoindol-2-yl)-2,3-dihydro-2-benzofuran-carboxylicacid, methyl ester;2-[(4-chloro-6-(ethylamino-1,3,5-triazin-2-yl)-amino]-2-methylpropanenitrile;or 1-methyl-2(1H)-pyrimidinone.
 8. A fragment of the isolated DNAmolecule of claim 2 in plasmid pUC18-SU1-BamHI as deposited with theAmerican Type Culture Collection as deposit number
 67780. 9. A fragmentof the isolated DNA molecule of claim 1 comprising the sequence encodingiron-sulfur protein FeS-B running in the downstream direction from baseposition 1369 to
 1578. 10. A fragment of the isolated DNA molecule ofclaim 3 comprising the DNA sequence encoding cytochrome P450 enzymeP450SU2 running in the downstream direction from base position 195 tobase position
 1406. 11. A fragment of the isolated DNA molecule of claim3 comprising the sequence encoding iron-sulfur protein FeS-A running inthe downstream direction from base position 1452 to
 1646. 12. Acombination of the isolated molecule DNA sequence of claim 2 and anisolated DNA molecule encoding iron sulfur protein FeS-A comprising##STR14##
 13. A combination of the isolated molecule DNA sequence ofclaim 4 and an isolated DNA molecule encoding iron sulfur protein FeS-Bcomprising ##STR15##
 14. A fragment of the isolated DNA molecule ofclaim 4 in plasmid pUC19-SU2-8 as deposited with the American TypeCulture Collection as accession number 67781.